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java.lang.Objectweka.attributeSelection.ASEvaluation
weka.attributeSelection.SubsetEvaluator
weka.attributeSelection.WrapperSubsetEval
public class WrapperSubsetEval
WrapperSubsetEval:
Evaluates attribute sets by using a learning scheme. Cross validation is used to estimate the accuracy of the learning scheme for a set of attributes.
For more information see:
Ron Kohavi, George H. John (1997). Wrappers for feature subset selection. Artificial Intelligence. 97(1-2):273-324.
@article{Kohavi1997, author = {Ron Kohavi and George H. John}, journal = {Artificial Intelligence}, note = {Special issue on relevance}, number = {1-2}, pages = {273-324}, title = {Wrappers for feature subset selection}, volume = {97}, year = {1997}, ISSN = {0004-3702} }Valid options are:
-B <base learner> class name of base learner to use for accuracy estimation. Place any classifier options LAST on the command line following a "--". eg.: -B weka.classifiers.bayes.NaiveBayes ... -- -K (default: weka.classifiers.rules.ZeroR)
-F <num> number of cross validation folds to use for estimating accuracy. (default=5)
-R <seed> Seed for cross validation accuracy testimation. (default = 1)
-T <num> threshold by which to execute another cross validation (standard deviation---expressed as a percentage of the mean). (default: 0.01 (1%))
Options specific to scheme weka.classifiers.rules.ZeroR:
-D If set, classifier is run in debug mode and may output additional info to the console
Constructor Summary | |
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WrapperSubsetEval()
Constructor. |
Method Summary | |
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void |
buildEvaluator(Instances data)
Generates a attribute evaluator. |
java.lang.String |
classifierTipText()
Returns the tip text for this property |
double |
evaluateSubset(java.util.BitSet subset)
Evaluates a subset of attributes |
java.lang.String |
foldsTipText()
Returns the tip text for this property |
Capabilities |
getCapabilities()
Returns the capabilities of this evaluator. |
Classifier |
getClassifier()
Get the classifier used as the base learner. |
int |
getFolds()
Get the number of folds used for accuracy estimation |
java.lang.String[] |
getOptions()
Gets the current settings of WrapperSubsetEval. |
int |
getSeed()
Get the random number seed used for cross validation |
TechnicalInformation |
getTechnicalInformation()
Returns an instance of a TechnicalInformation object, containing detailed information about the technical background of this class, e.g., paper reference or book this class is based on. |
double |
getThreshold()
Get the value of the threshold |
java.lang.String |
globalInfo()
Returns a string describing this attribute evaluator |
java.util.Enumeration |
listOptions()
Returns an enumeration describing the available options. |
static void |
main(java.lang.String[] args)
Main method for testing this class. |
java.lang.String |
seedTipText()
Returns the tip text for this property |
void |
setClassifier(Classifier newClassifier)
Set the classifier to use for accuracy estimation |
void |
setFolds(int f)
Set the number of folds to use for accuracy estimation |
void |
setOptions(java.lang.String[] options)
Parses a given list of options. |
void |
setSeed(int s)
Set the seed to use for cross validation |
void |
setThreshold(double t)
Set the value of the threshold for repeating cross validation |
java.lang.String |
thresholdTipText()
Returns the tip text for this property |
java.lang.String |
toString()
Returns a string describing the wrapper |
Methods inherited from class weka.attributeSelection.ASEvaluation |
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forName, makeCopies, postProcess |
Methods inherited from class java.lang.Object |
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equals, getClass, hashCode, notify, notifyAll, wait, wait, wait |
Constructor Detail |
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public WrapperSubsetEval()
Method Detail |
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public java.lang.String globalInfo()
public TechnicalInformation getTechnicalInformation()
getTechnicalInformation
in interface TechnicalInformationHandler
public java.util.Enumeration listOptions()
listOptions
in interface OptionHandler
public void setOptions(java.lang.String[] options) throws java.lang.Exception
-B <base learner> class name of base learner to use for accuracy estimation. Place any classifier options LAST on the command line following a "--". eg.: -B weka.classifiers.bayes.NaiveBayes ... -- -K (default: weka.classifiers.rules.ZeroR)
-F <num> number of cross validation folds to use for estimating accuracy. (default=5)
-R <seed> Seed for cross validation accuracy testimation. (default = 1)
-T <num> threshold by which to execute another cross validation (standard deviation---expressed as a percentage of the mean). (default: 0.01 (1%))
Options specific to scheme weka.classifiers.rules.ZeroR:
-D If set, classifier is run in debug mode and may output additional info to the console
setOptions
in interface OptionHandler
options
- the list of options as an array of strings
java.lang.Exception
- if an option is not supportedpublic java.lang.String thresholdTipText()
public void setThreshold(double t)
t
- the value of the thresholdpublic double getThreshold()
public java.lang.String foldsTipText()
public void setFolds(int f)
f
- the number of foldspublic int getFolds()
public java.lang.String seedTipText()
public void setSeed(int s)
s
- the seedpublic int getSeed()
public java.lang.String classifierTipText()
public void setClassifier(Classifier newClassifier)
newClassifier
- the Classifier to use.public Classifier getClassifier()
public java.lang.String[] getOptions()
getOptions
in interface OptionHandler
public Capabilities getCapabilities()
getCapabilities
in interface CapabilitiesHandler
getCapabilities
in class ASEvaluation
Capabilities
public void buildEvaluator(Instances data) throws java.lang.Exception
buildEvaluator
in class ASEvaluation
data
- set of instances serving as training data
java.lang.Exception
- if the evaluator has not been
generated successfullypublic double evaluateSubset(java.util.BitSet subset) throws java.lang.Exception
evaluateSubset
in class SubsetEvaluator
subset
- a bitset representing the attribute subset to be
evaluated
java.lang.Exception
- if the subset could not be evaluatedpublic java.lang.String toString()
toString
in class java.lang.Object
public static void main(java.lang.String[] args)
args
- the options
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