Package weka.filters.unsupervised.attribute

Class RemoveUseless

java.lang.Object
weka.filters.Filter
weka.filters.unsupervised.attribute.RemoveUseless
All Implemented Interfaces:
Serializable, CapabilitiesHandler, CapabilitiesIgnorer, CommandlineRunnable, OptionHandler, RevisionHandler, WeightedAttributesHandler, WeightedInstancesHandler, UnsupervisedFilter
public class RemoveUseless extends Filter implements UnsupervisedFilter, OptionHandler, WeightedInstancesHandler, WeightedAttributesHandler
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 options are: 

 -M <max variance %>
  Maximum variance percentage allowed (default 99). Specifically, if
  (number_of_distinct_values / total_number_of_values * 100)
  is greater than this value, then the attribute will be removed.
Version:
$Revision: 14508 $
Author:
Richard Kirkby (rkirkby@cs.waikato.ac.nz)
See Also:

  • Constructor Details

    • RemoveUseless

      public RemoveUseless()

  • Method Details

    • getCapabilities

      public Capabilities getCapabilities()
      Returns the Capabilities of this filter.
      Specified by:
      getCapabilities in interface CapabilitiesHandler
      Overrides:
      getCapabilities in class Filter
      Returns:
      the capabilities of this object
      See Also:

    • setInputFormat

      public boolean setInputFormat(Instances instanceInfo) throws Exception
      Sets the format of the input instances.
      Overrides:
      setInputFormat in class Filter
      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:
      Exception - if the inputFormat can't be set successfully

    • input

      public boolean input(Instance instance)
      Input an instance for filtering.
      Overrides:
      input in class Filter
      Parameters:
      instance - the input instance
      Returns:
      true if the filtered instance may now be collected with output().

    • batchFinished

      public boolean batchFinished() throws Exception
      Signify that this batch of input to the filter is finished.
      Overrides:
      batchFinished in class Filter
      Returns:
      true if there are instances pending output
      Throws:
      Exception - if no input format defined

    • listOptions

      public Enumeration<Option> listOptions()
      Returns an enumeration describing the available options.
      Specified by:
      listOptions in interface OptionHandler
      Overrides:
      listOptions in class Filter
      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: 

       -M <max variance %>
  Maximum variance percentage allowed (default 99). Specifically, if
  (number_of_distinct_values / total_number_of_values * 100)
  is greater than this value, then the attribute will be removed.
      Specified by:
      setOptions in interface OptionHandler
      Overrides:
      setOptions in class Filter
      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 filter.
      Specified by:
      getOptions in interface OptionHandler
      Overrides:
      getOptions in class Filter
      Returns:
      an array of strings suitable for passing to setOptions

    • globalInfo

      public String globalInfo()
      Returns a string describing this filter
      Returns:
      a description of the filter suitable for displaying in the explorer/experimenter gui

    • maximumVariancePercentageAllowedTipText

      public String maximumVariancePercentageAllowedTipText()
      Returns the tip text for this property
      Returns:
      tip text for this property suitable for displaying in the explorer/experimenter gui

    • 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

    • 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

    • getRevision

      public String getRevision()
      Returns the revision string.
      Specified by:
      getRevision in interface RevisionHandler
      Overrides:
      getRevision in class Filter
      Returns:
      the revision

    • main

      public static void main(String[] argv)
      Main method for testing this class.
      Parameters:
      argv - should contain arguments to the filter: use -h for help