Package weka.attributeSelection

Class LFSMethods

  • All Implemented Interfaces:
    RevisionHandler
    public class LFSMethods
extends java.lang.Object
implements RevisionHandler
    Version:
    $Revision: 1.3 $
    Author:
    Martin Guetlein (martin.guetlein@gmail.com)

    • Nested Class Summary

      Nested Classes 
      Modifier and Type Class Description
      class  LFSMethods.Link2
      Class for a node in a linked list.
      class  LFSMethods.LinkedList2
      Class for handling a linked list.

    • Constructor Summary

      Constructors 
      Constructor Description
      LFSMethods()
      empty constructor methods are not static because of access to inner class Link2 and LinkedList2

    • Constructor Detail

      • LFSMethods

        public LFSMethods()
        empty constructor methods are not static because of access to inner class Link2 and LinkedList2

    • Method Detail

      • getBestGroup

        public java.util.BitSet getBestGroup()
        Returns:
        best group found by forwardSearch/floatingForwardSearch

      • getBestMerit

        public double getBestMerit()
        Returns:
        merit of best group found by forwardSearch/floatingForwardSearch

      • getBestGroupOfSize

        public java.util.BitSet getBestGroupOfSize​(int size)
        Returns:
        best group of size found by forwardSearch

      • getNumEvalsCached

        public int getNumEvalsCached()
        Returns:
        number of cached / not performed evaluations

      • getNumEvalsTotal

        public int getNumEvalsTotal()
        Returns:
        number totally performed evaluations

      • rankAttributes

        public int[] rankAttributes​(Instances data,
                            SubsetEvaluator evaluator,
                            boolean verbose)
                     throws java.lang.Exception
        Returns:
        ranking (integer array) of attributes in data with evaluator (sorting is NOT stable!)
        Throws:
        java.lang.Exception

      • forwardSearch

        public java.util.BitSet forwardSearch​(int cacheSize,
                                      java.util.BitSet startGroup,
                                      int[] ranking,
                                      int k,
                                      boolean incrementK,
                                      int maxStale,
                                      int forceResultSize,
                                      Instances data,
                                      SubsetEvaluator evaluator,
                                      boolean verbose)
                               throws java.lang.Exception
        Performs linear forward selection
        Parameters:
        cacheSize - chacheSize (times number of instances) to store already evaluated sets
        startGroup - start group for search (can be null)
        ranking - ranking of attributes (as produced by rankAttributes), no ranking would be [0,1,2,3,4..]
        k - number of top k attributes that are taken into account
        incrementK - true -> fixed-set, false -> fixed-width
        maxStale - number of times the search proceeds even though no improvement was found (1 = hill-climbing)
        forceResultSize - stopping criteria changed from no-improvement (forceResultSize=-1) to subset-size
        data -
        evaluator -
        verbose -
        Returns:
        BitSet, that cotains the best-group found
        Throws:
        java.lang.Exception

      • floatingForwardSearch

        public java.util.BitSet floatingForwardSearch​(int cacheSize,
                                              java.util.BitSet startGroup,
                                              int[] ranking,
                                              int k,
                                              boolean incrementK,
                                              int maxStale,
                                              Instances data,
                                              SubsetEvaluator evaluator,
                                              boolean verbose)
                                       throws java.lang.Exception
        Performs linear floating forward selection ( the stopping criteria cannot be changed to a specific size value )
        Parameters:
        cacheSize - chacheSize (times number of instances) to store already evaluated sets
        startGroup - start group for search (can be null)
        ranking - ranking of attributes (as produced by rankAttributes), no ranking would be [0,1,2,3,4..]
        k - number of top k attributes that are taken into account
        incrementK - true -> fixed-set, false -> fixed-width
        maxStale - number of times the search proceeds even though no improvement was found (1 = hill-climbing)
        data -
        evaluator -
        verbose -
        Returns:
        BitSet, that cotains the best-group found
        Throws:
        java.lang.Exception

      • getRevision

        public java.lang.String getRevision()
        Returns the revision string.
        Specified by:
        getRevision in interface RevisionHandler
        Returns:
        the revision