Package weka.attributeSelection

Class Ranker

  • All Implemented Interfaces:
    java.io.Serializable, RankedOutputSearch, StartSetHandler, OptionHandler, RevisionHandler
    public class Ranker
extends ASSearch
implements RankedOutputSearch, StartSetHandler, OptionHandler
    Ranker :

    Ranks attributes by their individual evaluations. Use in conjunction with attribute evaluators (ReliefF, GainRatio, Entropy etc).

    Valid options are: 

     -P <start set>
  Specify a starting set of attributes.
  Eg. 1,3,5-7.
  Any starting attributes specified are
  ignored during the ranking.
     -T <threshold>
  Specify a theshold by which attributes
  may be discarded from the ranking.
     -N <num to select>
  Specify number of attributes to select
    Version:
    $Revision: 1.26 $
    Author:
    Mark Hall (mhall@cs.waikato.ac.nz)
    See Also:
    Serialized Form

    • Constructor Summary

      Constructors 
      Constructor Description
      Ranker()
      Constructor

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      java.lang.String generateRankingTipText()
      Returns the tip text for this property
      int getCalculatedNumToSelect()
      Gets the calculated number to select.
      boolean getGenerateRanking()
      This is a dummy method.
      int getNumToSelect()
      Gets the number of attributes to be retained.
      java.lang.String[] getOptions()
      Gets the current settings of ReliefFAttributeEval.
      java.lang.String getRevision()
      Returns the revision string.
      java.lang.String getStartSet()
      Returns a list of attributes (and or attribute ranges) as a String
      double getThreshold()
      Returns the threshold so that the AttributeSelection module can discard attributes from the ranking.
      java.lang.String globalInfo()
      Returns a string describing this search method
      java.util.Enumeration listOptions()
      Returns an enumeration describing the available options.
      java.lang.String numToSelectTipText()
      Returns the tip text for this property
      double[][] rankedAttributes()
      Sorts the evaluated attribute list
      int[] search​(ASEvaluation ASEval, Instances data)
      Kind of a dummy search algorithm.
      void setGenerateRanking​(boolean doRank)
      This is a dummy set method---Ranker is ONLY capable of producing a ranked list of attributes for attribute evaluators.
      void setNumToSelect​(int n)
      Specify the number of attributes to select from the ranked list.
      void setOptions​(java.lang.String[] options)
      Parses a given list of options.
      void setStartSet​(java.lang.String startSet)
      Sets a starting set of attributes for the search.
      void setThreshold​(double threshold)
      Set the threshold by which the AttributeSelection module can discard attributes.
      java.lang.String startSetTipText()
      Returns the tip text for this property
      java.lang.String thresholdTipText()
      Returns the tip text for this property
      java.lang.String toString()
      returns a description of the search as a String

      • Methods inherited from class java.lang.Object

        equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

    • Constructor Detail

      • Ranker

        public Ranker()
        Constructor

    • Method Detail

      • globalInfo

        public java.lang.String globalInfo()
        Returns a string describing this search method
        Returns:
        a description of the search suitable for displaying in the explorer/experimenter gui

      • numToSelectTipText

        public java.lang.String numToSelectTipText()
        Returns the tip text for this property
        Returns:
        tip text for this property suitable for displaying in the explorer/experimenter gui

      • setNumToSelect

        public void setNumToSelect​(int n)
        Specify the number of attributes to select from the ranked list. -1 indicates that all attributes are to be retained.
        Specified by:
        setNumToSelect in interface RankedOutputSearch
        Parameters:
        n - the number of attributes to retain

      • getNumToSelect

        public int getNumToSelect()
        Gets the number of attributes to be retained.
        Specified by:
        getNumToSelect in interface RankedOutputSearch
        Returns:
        the number of attributes to retain

      • getCalculatedNumToSelect

        public int getCalculatedNumToSelect()
        Gets the calculated number to select. This might be computed from a threshold, or if < 0 is set as the number to select then it is set to the number of attributes in the (transformed) data.
        Specified by:
        getCalculatedNumToSelect in interface RankedOutputSearch
        Returns:
        the calculated number of attributes to select

      • thresholdTipText

        public java.lang.String thresholdTipText()
        Returns the tip text for this property
        Returns:
        tip text for this property suitable for displaying in the explorer/experimenter gui

      • setThreshold

        public void setThreshold​(double threshold)
        Set the threshold by which the AttributeSelection module can discard attributes.
        Specified by:
        setThreshold in interface RankedOutputSearch
        Parameters:
        threshold - the threshold.

      • getThreshold

        public double getThreshold()
        Returns the threshold so that the AttributeSelection module can discard attributes from the ranking.
        Specified by:
        getThreshold in interface RankedOutputSearch
        Returns:
        a threshold by which to discard attributes

      • generateRankingTipText

        public java.lang.String generateRankingTipText()
        Returns the tip text for this property
        Returns:
        tip text for this property suitable for displaying in the explorer/experimenter gui

      • setGenerateRanking

        public void setGenerateRanking​(boolean doRank)
        This is a dummy set method---Ranker is ONLY capable of producing a ranked list of attributes for attribute evaluators.
        Specified by:
        setGenerateRanking in interface RankedOutputSearch
        Parameters:
        doRank - this parameter is N/A and is ignored

      • getGenerateRanking

        public boolean getGenerateRanking()
        This is a dummy method. Ranker can ONLY be used with attribute evaluators and as such can only produce a ranked list of attributes
        Specified by:
        getGenerateRanking in interface RankedOutputSearch
        Returns:
        true all the time.

      • startSetTipText

        public java.lang.String startSetTipText()
        Returns the tip text for this property
        Returns:
        tip text for this property suitable for displaying in the explorer/experimenter gui

      • setStartSet

        public void setStartSet​(java.lang.String startSet)
                 throws java.lang.Exception
        Sets a starting set of attributes for the search. It is the search method's responsibility to report this start set (if any) in its toString() method.
        Specified by:
        setStartSet in interface StartSetHandler
        Parameters:
        startSet - a string containing a list of attributes (and or ranges), eg. 1,2,6,10-15.
        Throws:
        java.lang.Exception - if start set can't be set.

      • getStartSet

        public java.lang.String getStartSet()
        Returns a list of attributes (and or attribute ranges) as a String
        Specified by:
        getStartSet in interface StartSetHandler
        Returns:
        a list of attributes (and or attribute ranges)

      • listOptions

        public java.util.Enumeration listOptions()
        Returns an enumeration describing the available options.
        Specified by:
        listOptions in interface OptionHandler
        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: 

         -P <start set>
  Specify a starting set of attributes.
  Eg. 1,3,5-7.
  Any starting attributes specified are
  ignored during the ranking.
         -T <threshold>
  Specify a theshold by which attributes
  may be discarded from the ranking.
         -N <num to select>
  Specify number of attributes to select
        Specified by:
        setOptions in interface OptionHandler
        Parameters:
        options - the list of options as an array of strings
        Throws:
        java.lang.Exception - if an option is not supported

      • getOptions

        public java.lang.String[] getOptions()
        Gets the current settings of ReliefFAttributeEval.
        Specified by:
        getOptions in interface OptionHandler
        Returns:
        an array of strings suitable for passing to setOptions()

      • search

        public int[] search​(ASEvaluation ASEval,
                    Instances data)
             throws java.lang.Exception
        Kind of a dummy search algorithm. Calls a Attribute evaluator to evaluate each attribute not included in the startSet and then sorts them to produce a ranked list of attributes.
        Specified by:
        search in class ASSearch
        Parameters:
        ASEval - the attribute evaluator to guide the search
        data - the training instances.
        Returns:
        an array (not necessarily ordered) of selected attribute indexes
        Throws:
        java.lang.Exception - if the search can't be completed

      • rankedAttributes

        public double[][] rankedAttributes()
                            throws java.lang.Exception
        Sorts the evaluated attribute list
        Specified by:
        rankedAttributes in interface RankedOutputSearch
        Returns:
        an array of sorted (highest eval to lowest) attribute indexes
        Throws:
        java.lang.Exception - of sorting can't be done.

      • toString

        public java.lang.String toString()
        returns a description of the search as a String
        Overrides:
        toString in class java.lang.Object
        Returns:
        a description of the search