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java.lang.Objectweka.attributeSelection.ASEvaluation
weka.attributeSelection.UnsupervisedAttributeEvaluator
weka.attributeSelection.PrincipalComponents
public class PrincipalComponents
Performs a principal components analysis and transformation of the data. Use in conjunction with a Ranker search. Dimensionality reduction is accomplished by choosing enough eigenvectors to account for some percentage of the variance in the original data---default 0.95 (95%). Attribute noise can be filtered by transforming to the PC space, eliminating some of the worst eigenvectors, and then transforming back to the original space.
Valid options are:-D Don't normalize input data.
-R Retain enough PC attributes to account for this proportion of variance in the original data. (default = 0.95)
-O Transform through the PC space and back to the original space.
-A Maximum number of attributes to include in transformed attribute names. (-1 = include all)
Constructor Summary | |
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PrincipalComponents()
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Method Summary | |
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void |
buildEvaluator(Instances data)
Initializes principal components and performs the analysis |
java.lang.String |
centerDataTipText()
Returns the tip text for this property |
Instance |
convertInstance(Instance instance)
Transform an instance in original (unormalized) format. |
double |
evaluateAttribute(int att)
Evaluates the merit of a transformed attribute. |
Capabilities |
getCapabilities()
Returns the capabilities of this evaluator. |
boolean |
getCenterData()
Get whether to center (rather than standardize) the data. |
int |
getMaximumAttributeNames()
Gets maximum number of attributes to include in transformed attribute names. |
java.lang.String[] |
getOptions()
Gets the current settings of PrincipalComponents |
java.lang.String |
getRevision()
Returns the revision string. |
boolean |
getTransformBackToOriginal()
Gets whether the data is to be transformed back to the original space. |
double |
getVarianceCovered()
Gets the proportion of total variance to account for when retaining principal components |
java.lang.String |
globalInfo()
Returns a string describing this attribute transformer |
java.util.Enumeration |
listOptions()
Returns an enumeration describing the available options. |
static void |
main(java.lang.String[] argv)
Main method for testing this class |
java.lang.String |
maximumAttributeNamesTipText()
Returns the tip text for this property |
void |
setCenterData(boolean center)
Set whether to center (rather than standardize) the data. |
void |
setMaximumAttributeNames(int m)
Sets maximum number of attributes to include in transformed attribute names. |
void |
setOptions(java.lang.String[] options)
Parses a given list of options. |
void |
setTransformBackToOriginal(boolean b)
Sets whether the data should be transformed back to the original space |
void |
setVarianceCovered(double vc)
Sets the amount of variance to account for when retaining principal components |
java.lang.String |
toString()
Returns a description of this attribute transformer |
java.lang.String |
transformBackToOriginalTipText()
Returns the tip text for this property |
Instances |
transformedData(Instances data)
Gets the transformed training data. |
Instances |
transformedHeader()
Returns just the header for the transformed data (ie. |
java.lang.String |
varianceCoveredTipText()
Returns the tip text for this property |
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 PrincipalComponents()
Method Detail |
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public java.lang.String globalInfo()
public java.util.Enumeration listOptions()
listOptions
in interface OptionHandler
public void setOptions(java.lang.String[] options) throws java.lang.Exception
-D Don't normalize input data.
-R Retain enough PC attributes to account for this proportion of variance in the original data. (default = 0.95)
-O Transform through the PC space and back to the original space.
-A Maximum number of attributes to include in transformed attribute names. (-1 = include all)
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 centerDataTipText()
public void setCenterData(boolean center)
center
- true if the data is to be
centered rather than standardizedpublic boolean getCenterData()
public java.lang.String varianceCoveredTipText()
public void setVarianceCovered(double vc)
vc
- the proportion of total variance to account forpublic double getVarianceCovered()
public java.lang.String maximumAttributeNamesTipText()
public void setMaximumAttributeNames(int m)
m
- the maximum number of attributespublic int getMaximumAttributeNames()
public java.lang.String transformBackToOriginalTipText()
public void setTransformBackToOriginal(boolean b)
b
- true if the data should be transformed back to the
original spacepublic boolean getTransformBackToOriginal()
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
- the instances to analyse/transform
java.lang.Exception
- if analysis failspublic Instances transformedHeader() throws java.lang.Exception
transformedHeader
in interface AttributeTransformer
java.lang.Exception
- if the header of the transformed data can't
be determined.public Instances transformedData(Instances data) throws java.lang.Exception
transformedData
in interface AttributeTransformer
java.lang.Exception
- if transformed data can't be returnedpublic double evaluateAttribute(int att) throws java.lang.Exception
evaluateAttribute
in interface AttributeEvaluator
att
- the attribute to be evaluated
java.lang.Exception
- if attribute can't be evaluatedpublic java.lang.String toString()
toString
in class java.lang.Object
public Instance convertInstance(Instance instance) throws java.lang.Exception
convertInstance
in interface AttributeTransformer
instance
- an instance in the original (unormalized) format
java.lang.Exception
- if instance cant be transformedpublic java.lang.String getRevision()
getRevision
in interface RevisionHandler
getRevision
in class ASEvaluation
public static void main(java.lang.String[] argv)
argv
- should contain the command line arguments to the
evaluator/transformer (see AttributeSelection)
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