Package weka.attributeSelection

Class RankSearch

  • All Implemented Interfaces:
    java.io.Serializable, OptionHandler, RevisionHandler, TechnicalInformationHandler
    public class RankSearch
extends ASSearch
implements OptionHandler, TechnicalInformationHandler
    RankSearch :

    Uses an attribute/subset evaluator to rank all attributes. If a subset evaluator is specified, then a forward selection search is used to generate a ranked list. From the ranked list of attributes, subsets of increasing size are evaluated, ie. The best attribute, the best attribute plus the next best attribute, etc.... The best attribute set is reported. RankSearch is linear in the number of attributes if a simple attribute evaluator is used such as GainRatioAttributeEval. For more information see:

    Mark Hall, Geoffrey Holmes (2003). Benchmarking attribute selection techniques for discrete class data mining. IEEE Transactions on Knowledge and Data Engineering. 15(6):1437-1447.

    Valid options are: 

     -A <attribute evaluator>
  class name of attribute evaluator to use for ranking. Place any
  evaluator options LAST on the command line following a "--".
  eg.:
   -A weka.attributeSelection.GainRatioAttributeEval ... -- -M
  (default: weka.attributeSelection.GainRatioAttributeEval)
     -S <step size>
  number of attributes to be added from the
  ranking in each iteration (default = 1).
     -R <start point>
  point in the ranking to start evaluating from. 
  (default = 0, ie. the head of the ranking).
     
 Options specific to evaluator weka.attributeSelection.GainRatioAttributeEval:
 
     -M
  treat missing values as a seperate value.
    Version:
    $Revision: 6253 $
    Author:
    Mark Hall (mhall@cs.waikato.ac.nz)
    See Also:
    Serialized Form

    • Constructor Summary

      Constructors 
      Constructor Description
      RankSearch()
      Constructor

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      java.lang.String attributeEvaluatorTipText()
      Returns the tip text for this property
      ASEvaluation getAttributeEvaluator()
      Get the attribute evaluator used to generate the ranking.
      java.lang.String[] getOptions()
      Gets the current settings of WrapperSubsetEval.
      java.lang.String getRevision()
      Returns the revision string.
      int getStartPoint()
      Get the point at which to start evaluating the ranking
      int getStepSize()
      Get the number of attributes to add from the rankining in each iteration
      TechnicalInformation getTechnicalInformation()
      Returns an instance of a TechnicalInformation object, containing detailed information about the technical background of this class, e.g., paper reference or book this class is based on.
      java.lang.String globalInfo()
      Returns a string describing this search method
      java.util.Enumeration listOptions()
      Returns an enumeration describing the available options.
      int[] search​(ASEvaluation ASEval, Instances data)
      Ranks attributes using the specified attribute evaluator and then searches the ranking using the supplied subset evaluator.
      void setAttributeEvaluator​(ASEvaluation newEvaluator)
      Set the attribute evaluator to use for generating the ranking.
      void setOptions​(java.lang.String[] options)
      Parses a given list of options.
      void setStartPoint​(int sp)
      Set the point at which to start evaluating the ranking
      void setStepSize​(int ss)
      Set the number of attributes to add from the rankining in each iteration
      java.lang.String startPointTipText()
      Returns the tip text for this property
      java.lang.String stepSizeTipText()
      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

      • RankSearch

        public RankSearch()
        Constructor

    • Method Detail

      • globalInfo

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

      • getTechnicalInformation

        public TechnicalInformation getTechnicalInformation()
        Returns an instance of a TechnicalInformation object, containing detailed information about the technical background of this class, e.g., paper reference or book this class is based on.
        Specified by:
        getTechnicalInformation in interface TechnicalInformationHandler
        Returns:
        the technical information about this class

      • attributeEvaluatorTipText

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

      • setAttributeEvaluator

        public void setAttributeEvaluator​(ASEvaluation newEvaluator)
        Set the attribute evaluator to use for generating the ranking.
        Parameters:
        newEvaluator - the attribute evaluator to use.

      • getAttributeEvaluator

        public ASEvaluation getAttributeEvaluator()
        Get the attribute evaluator used to generate the ranking.
        Returns:
        the evaluator used to generate the ranking.

      • stepSizeTipText

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

      • setStepSize

        public void setStepSize​(int ss)
        Set the number of attributes to add from the rankining in each iteration
        Parameters:
        ss - the number of attribes to add.

      • getStepSize

        public int getStepSize()
        Get the number of attributes to add from the rankining in each iteration
        Returns:
        the number of attributes to add.

      • startPointTipText

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

      • setStartPoint

        public void setStartPoint​(int sp)
        Set the point at which to start evaluating the ranking
        Parameters:
        sp - the position in the ranking to start at

      • getStartPoint

        public int getStartPoint()
        Get the point at which to start evaluating the ranking
        Returns:
        the position in the ranking to start at

      • 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: 

         -A <attribute evaluator>
  class name of attribute evaluator to use for ranking. Place any
  evaluator options LAST on the command line following a "--".
  eg.:
   -A weka.attributeSelection.GainRatioAttributeEval ... -- -M
  (default: weka.attributeSelection.GainRatioAttributeEval)
         -S <step size>
  number of attributes to be added from the
  ranking in each iteration (default = 1).
         -R <start point>
  point in the ranking to start evaluating from. 
  (default = 0, ie. the head of the ranking).
         
 Options specific to evaluator weka.attributeSelection.GainRatioAttributeEval:
 
         -M
  treat missing values as a seperate value.
        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 WrapperSubsetEval.
        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
        Ranks attributes using the specified attribute evaluator and then searches the ranking using the supplied subset evaluator.
        Specified by:
        search in class ASSearch
        Parameters:
        ASEval - the subset 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

      • 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