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Class weka.attributeSelection.PrincipalComponents
java.lang.Object
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+----weka.attributeSelection.ASEvaluation
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+----weka.attributeSelection.AttributeEvaluator
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+----weka.attributeSelection.PrincipalComponents
- public class PrincipalComponents
- extends AttributeEvaluator
- implements AttributeTransformer, OptionHandler
Class for performing principal components analysis/transformation.
- Version:
- $Revision: 1.16 $
- Author:
- Mark Hall (mhall@cs.waikato.ac.nz)
PrincipalComponents()
-
buildEvaluator(Instances)
- Initializes principal components and performs the analysis
convertInstance(Instance)
- Transform an instance in original (unormalized) format.
evaluateAttribute(int)
- Evaluates the merit of a transformed attribute.
getNormalize()
- Gets whether or not input data is to be normalized
getOptions()
- Gets the current settings of PrincipalComponents
getTransformBackToOriginal()
- Gets whether the data is to be transformed back to the original
space.
getVarianceCovered()
- Gets the proportion of total variance to account for when
retaining principal components
globalInfo()
- Returns a string describing this attribute transformer
listOptions()
- Returns an enumeration describing the available options
-N
Don't normalize the input data.
main(String[])
- Main method for testing this class
normalizeTipText()
- Returns the tip text for this property
setNormalize(boolean)
- Set whether input data will be normalized.
setOptions(String[])
- Parses a given list of options.
setTransformBackToOriginal(boolean)
- Sets whether the data should be transformed back to the original
space
setVarianceCovered(double)
- Sets the amount of variance to account for when retaining
principal components
toString()
- Returns a description of this attribute transformer
transformBackToOriginalTipText()
- Returns the tip text for this property
transformedData()
- Gets the transformed training data.
transformedHeader()
- Returns just the header for the transformed data (ie.
varianceCoveredTipText()
- Returns the tip text for this property
PrincipalComponents
public PrincipalComponents()
globalInfo
public java.lang.String globalInfo()
Returns a string describing this attribute transformer
- Returns:
- a description of the evaluator suitable for
displaying in the explorer/experimenter gui
listOptions
public java.util.Enumeration listOptions()
Returns an enumeration describing the available options
-N
Don't normalize the input data.
- 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.
Valid options are:
-N
Don't normalize the input data.
- Parameters:
options
- the list of options as an array of strings
- Throws:
- java.lang.Exception - if an option is not supported
normalizeTipText
public java.lang.String normalizeTipText()
Returns the tip text for this property
- Returns:
- tip text for this property suitable for
displaying in the explorer/experimenter gui
setNormalize
public void setNormalize(boolean n)
Set whether input data will be normalized.
- Parameters:
n
- true if input data is to be normalized
getNormalize
public boolean getNormalize()
Gets whether or not input data is to be normalized
- Returns:
- true if input data is to be normalized
varianceCoveredTipText
public java.lang.String varianceCoveredTipText()
Returns the tip text for this property
- Returns:
- tip text for this property suitable for
displaying in the explorer/experimenter gui
setVarianceCovered
public void setVarianceCovered(double vc)
Sets the amount of variance to account for when retaining
principal components
- Parameters:
vc
- the proportion of total variance to account for
getVarianceCovered
public double getVarianceCovered()
Gets the proportion of total variance to account for when
retaining principal components
- Returns:
- the proportion of variance to account for
transformBackToOriginalTipText
public java.lang.String transformBackToOriginalTipText()
Returns the tip text for this property
- Returns:
- tip text for this property suitable for
displaying in the explorer/experimenter gui
setTransformBackToOriginal
public void setTransformBackToOriginal(boolean b)
Sets whether the data should be transformed back to the original
space
- Parameters:
b
- true if the data should be transformed back to the
original space
getTransformBackToOriginal
public boolean getTransformBackToOriginal()
Gets whether the data is to be transformed back to the original
space.
- Returns:
- true if the data is to be transformed back to the original space
getOptions
public java.lang.String[] getOptions()
Gets the current settings of PrincipalComponents
- Returns:
- an array of strings suitable for passing to setOptions()
buildEvaluator
public void buildEvaluator(Instances data) throws java.lang.Exception
Initializes principal components and performs the analysis
- Parameters:
data
- the instances to analyse/transform
- Throws:
- java.lang.Exception - if analysis fails
- Overrides:
- buildEvaluator in class ASEvaluation
transformedHeader
public Instances transformedHeader() throws java.lang.Exception
Returns just the header for the transformed data (ie. an empty
set of instances. This is so that AttributeSelection can
determine the structure of the transformed data without actually
having to get all the transformed data through getTransformedData().
- Returns:
- the header of the transformed data.
- Throws:
- java.lang.Exception - if the header of the transformed data can't
be determined.
transformedData
public Instances transformedData() throws java.lang.Exception
Gets the transformed training data.
- Returns:
- the transformed training data
- Throws:
- java.lang.Exception - if transformed data can't be returned
evaluateAttribute
public double evaluateAttribute(int att) throws java.lang.Exception
Evaluates the merit of a transformed attribute. This is defined
to be 1 minus the cumulative variance explained. Merit can't
be meaningfully evaluated if the data is to be transformed back
to the original space.
- Parameters:
att
- the attribute to be evaluated
- Returns:
- the merit of a transformed attribute
- Throws:
- java.lang.Exception - if attribute can't be evaluated
- Overrides:
- evaluateAttribute in class AttributeEvaluator
toString
public java.lang.String toString()
Returns a description of this attribute transformer
- Returns:
- a String describing this attribute transformer
- Overrides:
- toString in class java.lang.Object
convertInstance
public Instance convertInstance(Instance instance) throws java.lang.Exception
Transform an instance in original (unormalized) format. Convert back
to the original space if requested.
- Parameters:
instance
- an instance in the original (unormalized) format
- Returns:
- a transformed instance
- Throws:
- java.lang.Exception - if instance cant be transformed
main
public static void main(java.lang.String argv[])
Main method for testing this class
- Parameters:
argv
- should contain the command line arguments to the
evaluator/transformer (see AttributeSelection)
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