Class ConsistencySubsetEval

  • All Implemented Interfaces:
    java.io.Serializable, SubsetEvaluator, CapabilitiesHandler, RevisionHandler, TechnicalInformationHandler

    public class ConsistencySubsetEval
    extends ASEvaluation
    implements SubsetEvaluator, TechnicalInformationHandler
    ConsistencySubsetEval :

    Evaluates the worth of a subset of attributes by the level of consistency in the class values when the training instances are projected onto the subset of attributes.

    Consistency of any subset can never be lower than that of the full set of attributes, hence the usual practice is to use this subset evaluator in conjunction with a Random or Exhaustive search which looks for the smallest subset with consistency equal to that of the full set of attributes.

    For more information see:

    H. Liu, R. Setiono: A probabilistic approach to feature selection - A filter solution. In: 13th International Conference on Machine Learning, 319-327, 1996.

    BibTeX:

     @inproceedings{Liu1996,
        author = {H. Liu and R. Setiono},
        booktitle = {13th International Conference on Machine Learning},
        pages = {319-327},
        title = {A probabilistic approach to feature selection - A filter solution},
        year = {1996}
     }
     

    Version:
    $Revision: 11851 $
    Author:
    Mark Hall (mhall@cs.waikato.ac.nz)
    See Also:
    Discretize, Serialized Form
    • Constructor Detail

      • ConsistencySubsetEval

        public ConsistencySubsetEval()
        Constructor. Calls restOptions to set default options
    • 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
      • 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
      • buildEvaluator

        public void buildEvaluator​(Instances data)
                            throws java.lang.Exception
        Generates a attribute evaluator. Has to initialize all fields of the evaluator that are not being set via options.
        Specified by:
        buildEvaluator in class ASEvaluation
        Parameters:
        data - set of instances serving as training data
        Throws:
        java.lang.Exception - if the evaluator has not been generated successfully
      • evaluateSubset

        public double evaluateSubset​(java.util.BitSet subset)
                              throws java.lang.Exception
        Evaluates a subset of attributes
        Specified by:
        evaluateSubset in interface SubsetEvaluator
        Parameters:
        subset - a bitset representing the attribute subset to be evaluated
        Returns:
        the "merit" of the subset
        Throws:
        java.lang.Exception - if the subset could not be evaluated
      • toString

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

        public void clean()
        Description copied from class: ASEvaluation
        Tells the evaluator that the attribute selection process is complete. It can then clean up data structures, references to training data as necessary in order to save memory
        Overrides:
        clean in class ASEvaluation
      • main

        public static void main​(java.lang.String[] args)
        Main method for testing this class.
        Parameters:
        args - the options