Package weka.classifiers

Class CheckClassifier

java.lang.Object

weka.core.Check

weka.core.CheckScheme

weka.classifiers.CheckClassifier

All Implemented Interfaces:

OptionHandler, RevisionHandler

public class CheckClassifier
extends CheckScheme

Class for examining the capabilities and finding problems with classifiers. If you implement a classifier using the WEKA.libraries, you should run the checks on it to ensure robustness and correct operation. Passing all the tests of this object does not mean bugs in the classifier don't exist, but this will help find some common ones.

Typical usage:

java weka.classifiers.CheckClassifier -W classifier_name classifier_options

CheckClassifier reports on the following:

• Classifier abilities
  • Possible command line options to the classifier
  • Whether the classifier can predict nominal, numeric, string, date or relational class attributes. Warnings will be displayed if performance is worse than ZeroR
  • Whether the classifier can be trained incrementally
  • Whether the classifier can handle numeric predictor attributes
  • Whether the classifier can handle nominal predictor attributes
  • Whether the classifier can handle string predictor attributes
  • Whether the classifier can handle date predictor attributes
  • Whether the classifier can handle relational predictor attributes
  • Whether the classifier can handle multi-instance data
  • Whether the classifier can handle missing predictor values
  • Whether the classifier can handle missing class values
  • Whether a nominal classifier only handles 2 class problems
  • Whether the classifier can handle instance weights
• Correct functioning
  • Correct initialisation during buildClassifier (i.e. no result changes when buildClassifier called repeatedly)
  • Whether incremental training produces the same results as during non-incremental training (which may or may not be OK)
  • Whether the classifier alters the data pased to it (number of instances, instance order, instance weights, etc)
  • Whether the toString() method works correctly before the classifier has been built.
• Degenerate cases
  • building classifier with zero training instances
  • all but one predictor attribute values missing
  • all predictor attribute values missing
  • all but one class values missing
  • all class values missing

Running CheckClassifier with the debug option set will output the training and test datasets for any failed tests.

The weka.classifiers.AbstractClassifierTest uses this class to test all the classifiers. Any changes here, have to be checked in that abstract test class, too.

Valid options are:

 -D
  Turn on debugging output.
 

 -S
  Silent mode - prints nothing to stdout.
 

 -N <num>
  The number of instances in the datasets (default 20).
 

 -nominal <num>
  The number of nominal attributes (default 2).
 

 -nominal-values <num>
  The number of values for nominal attributes (default 1).
 

 -numeric <num>
  The number of numeric attributes (default 1).
 

 -string <num>
  The number of string attributes (default 1).
 

 -date <num>
  The number of date attributes (default 1).
 

 -relational <num>
  The number of relational attributes (default 1).
 

 -num-instances-relational <num>
  The number of instances in relational/bag attributes (default 10).
 

 -words <comma-separated-list>
  The words to use in string attributes.
 

 -word-separators <chars>
  The word separators to use in string attributes.
 

 -W
  Full name of the classifier analysed.
  eg: weka.classifiers.bayes.NaiveBayes
  (default weka.classifiers.rules.ZeroR)
 

 Options specific to classifier weka.classifiers.rules.ZeroR:
 

 -D
  If set, classifier is run in debug mode and
  may output additional info to the console
 

Options after -- are passed to the designated classifier.

Version:

$Revision: 11253 $

Author:

Len Trigg (trigg@cs.waikato.ac.nz), FracPete (fracpete at waikato dot ac dot nz)

See Also:

• TestInstances

Nested Class Summary

Nested classes/interfaces inherited from class weka.core.CheckScheme

CheckScheme.PostProcessor

Constructor Summary

Constructors

Constructor	Description
CheckClassifier()

Method Summary

Modifier and Type	Method	Description
void	doTests()	Begin the tests, reporting results to System.out
Classifier	getClassifier()	Get the classifier used as the classifier
String[]	getOptions()	Gets the current settings of the CheckClassifier.
String	getRevision()	Returns the revision string.
Enumeration<Option>	listOptions()	Returns an enumeration describing the available options.
static void	main(String[] args)	Test method for this class
void	setClassifier(Classifier newClassifier)	Set the classifier for boosting.
void	setOptions(String[] options)	Parses a given list of options.

Methods inherited from class weka.core.CheckScheme

attributeTypeToString, getNumDate, getNumInstances, getNumInstancesRelational, getNumNominal, getNumNumeric, getNumRelational, getNumString, getPostProcessor, getWords, getWordSeparators, hasClasspathProblems, setNumDate, setNumInstances, setNumInstancesRelational, setNumNominal, setNumNumeric, setNumRelational, setNumString, setPostProcessor, setWords, setWordSeparators

Methods inherited from class weka.core.Check

getDebug, getSilent, setDebug, setSilent

Methods inherited from class java.lang.Object

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

Constructor Details

CheckClassifier

public CheckClassifier()

Method Details

listOptions

public Enumeration<Option> listOptions()

Returns an enumeration describing the available options.

Specified by:

listOptions in interface OptionHandler

Overrides:

listOptions in class CheckScheme

Returns:

an enumeration of all the available options.

setOptions

public void setOptions(String[] options)
                throws Exception

Parses a given list of options. Valid options are:

 -D
  Turn on debugging output.
 

 -S
  Silent mode - prints nothing to stdout.
 

 -N <num>
  The number of instances in the datasets (default 20).
 

 -nominal <num>
  The number of nominal attributes (default 2).
 

 -nominal-values <num>
  The number of values for nominal attributes (default 1).
 

 -numeric <num>
  The number of numeric attributes (default 1).
 

 -string <num>
  The number of string attributes (default 1).
 

 -date <num>
  The number of date attributes (default 1).
 

 -relational <num>
  The number of relational attributes (default 1).
 

 -num-instances-relational <num>
  The number of instances in relational/bag attributes (default 10).
 

 -words <comma-separated-list>
  The words to use in string attributes.
 

 -word-separators <chars>
  The word separators to use in string attributes.
 

 -W
  Full name of the classifier analysed.
  eg: weka.classifiers.bayes.NaiveBayes
  (default weka.classifiers.rules.ZeroR)
 

 Options specific to classifier weka.classifiers.rules.ZeroR:
 

 -D
  If set, classifier is run in debug mode and
  may output additional info to the console
 

Specified by:

setOptions in interface OptionHandler

Overrides:

setOptions in class CheckScheme

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 CheckClassifier.

Specified by:

getOptions in interface OptionHandler

Overrides:

getOptions in class CheckScheme

Returns:

an array of strings suitable for passing to setOptions

doTests

public void doTests()

Begin the tests, reporting results to System.out

Specified by:

doTests in class CheckScheme

setClassifier

public void setClassifier(Classifier newClassifier)

Set the classifier for boosting.

Parameters:

newClassifier - the Classifier to use.

getClassifier

public Classifier getClassifier()

Get the classifier used as the classifier

Returns:

the classifier used as the classifier

getRevision

public String getRevision()

Returns the revision string.

Returns:

the revision

main

public static void main(String[] args)

Test method for this class

Parameters:

args - the commandline parameters