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Class weka.filters.unsupervised.attribute.RemoveUseless 

java.lang.Object
    |
    +----weka.filters.Filter
            |
            +----weka.filters.unsupervised.attribute.RemoveUseless
public class RemoveUseless
extends Filter
implements UnsupervisedFilter, OptionHandler
This filter removes attributes that do not vary at all or that vary too much. All constant attributes are deleted automatically, along with any that exceed the maximum percentage of variance parameter. The maximum variance test is only applied to nominal attributes.

Valid filter-specific options are:

-M percentage
The maximum variance allowed before an attribute will be deleted (default 100).

Version:
$Revision: 1.4 $
Author:
Richard Kirkby (rkirkby@cs.waikato.ac.nz)

Constructor Index

o RemoveUseless()
 

Method Index

o batchFinished()
Signify that this batch of input to the filter is finished.
o getMaximumVariancePercentageAllowed()
Gets the maximum variance attributes are allowed to have before they are deleted by the filter.
o getOptions()
Gets the current settings of the filter.
o globalInfo()
Returns a string describing this filter
o input(Instance)
Input an instance for filtering.
o listOptions()
Returns an enumeration describing the available options.
o main(String[])
Main method for testing this class.
o maximumVariancePercentageAllowedTipText()
Returns the tip text for this property
o setInputFormat(Instances)
Sets the format of the input instances.
o setMaximumVariancePercentageAllowed(double)
Sets the maximum variance attributes are allowed to have before they are deleted by the filter.
o setOptions(String[])
Parses the options for this object.

Constructor Detail

o RemoveUseless
public RemoveUseless()

Method Detail

o setInputFormat
public boolean setInputFormat(Instances instanceInfo) throws java.lang.Exception
          Sets the format of the input instances.
Parameters:
instanceInfo - an Instances object containing the input instance structure (any instances contained in the object are ignored - only the structure is required).
Returns:
true if the outputFormat may be collected immediately
Throws:
java.lang.Exception - if the inputFormat can't be set successfully
Overrides:
setInputFormat in class Filter
o input
public boolean input(Instance instance)
          Input an instance for filtering.
Parameters:
instance - the input instance
Returns:
true if the filtered instance may now be collected with output().
Overrides:
input in class Filter
o batchFinished
public boolean batchFinished() throws java.lang.Exception
          Signify that this batch of input to the filter is finished.
Returns:
true if there are instances pending output
Overrides:
batchFinished in class Filter
o listOptions
public java.util.Enumeration listOptions()
          Returns an enumeration describing the available options.
Returns:
an enumeration of all the available options.
o setOptions
public void setOptions(java.lang.String options[]) throws java.lang.Exception
          Parses the options for this object. Valid options are:

-M percentage
The maximum variance allowed before an attribute will be deleted (default 100).

Parameters:
options - the list of options as an array of strings
Throws:
java.lang.Exception - if an option is not supported
o getOptions
public java.lang.String[] getOptions()
          Gets the current settings of the filter.
Returns:
an array of strings suitable for passing to setOptions
o globalInfo
public java.lang.String globalInfo()
          Returns a string describing this filter
Returns:
a description of the filter suitable for displaying in the explorer/experimenter gui
o maximumVariancePercentageAllowedTipText
public java.lang.String maximumVariancePercentageAllowedTipText()
          Returns the tip text for this property
Returns:
tip text for this property suitable for displaying in the explorer/experimenter gui
o setMaximumVariancePercentageAllowed
public void setMaximumVariancePercentageAllowed(double maxVariance)
          Sets the maximum variance attributes are allowed to have before they are deleted by the filter.
Parameters:
maxVariance - the maximum variance allowed, specified as a percentage
o getMaximumVariancePercentageAllowed
public double getMaximumVariancePercentageAllowed()
          Gets the maximum variance attributes are allowed to have before they are deleted by the filter.
Returns:
the maximum variance allowed, specified as a percentage
o main
public static void main(java.lang.String argv[])
          Main method for testing this class.
Parameters:
argv - should contain arguments to the filter: use -h for help 
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