content: /*
   *    This program is free software; you can redistribute it and/or modify
   *    it under the terms of the GNU General Public License as published by
   *    the Free Software Foundation; either version 2 of the License, or
   *    (at your option) any later version.
   *
   *    This program is distributed in the hope that it will be useful,
   *    but WITHOUT ANY WARRANTY; without even the implied warranty of
   *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   *    GNU General Public License for more details.
   *
   *    You should have received a copy of the GNU General Public License
   *    along with this program; if not, write to the Free Software
   *    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
   */
  
  /*
   *    ASEvaluation.java
   *    Copyright (C) 1999 University of Waikato, Hamilton, New Zealand
   *
   */
  
  
  package weka.attributeSelection;
  
  import weka.core.Capabilities;
  import weka.core.CapabilitiesHandler;
  import weka.core.Instances;
  import weka.core.RevisionHandler;
  import weka.core.RevisionUtils;
  import weka.core.SerializedObject;
  import weka.core.Utils;
  
  import java.io.Serializable;
  
  /** 
   * Abstract attribute selection evaluation class
   *
   * @author Mark Hall (mhall@cs.waikato.ac.nz)
   * @version $Revision: 6624 $
   */
  public abstract class ASEvaluation
    implements Serializable, CapabilitiesHandler, RevisionHandler {
  
    /** for serialization */
    private static final long serialVersionUID = 2091705669885950849L;
    
    // ===============
    // Public methods.
    // ===============
  
    /**
     * Generates a attribute evaluator. Has to initialize all fields of the 
     * evaluator that are not being set via options.
     *
     * @param data set of instances serving as training data 
     * @exception Exception if the evaluator has not been 
     * generated successfully
     */
    public abstract void buildEvaluator(Instances data) throws Exception;
  
    /**
     * Provides a chance for a attribute evaluator to do any special
     * post processing of the selected attribute set.
     *
     * @param attributeSet the set of attributes found by the search
     * @return a possibly ranked list of postprocessed attributes
     * @exception Exception if postprocessing fails for some reason
     */
    public int [] postProcess(int [] attributeSet) 
      throws Exception {
      return attributeSet;
    }
  
    /**
     * Creates a new instance of an attribute/subset evaluator 
     * given it's class name and
     * (optional) arguments to pass to it's setOptions method. If the
     * evaluator implements OptionHandler and the options parameter is
     * non-null, the evaluator will have it's options set.
     *
     * @param evaluatorName the fully qualified class name of the evaluator
     * @param options an array of options suitable for passing to setOptions. May
     * be null.
     * @return the newly created evaluator, ready for use.
     * @exception Exception if the evaluator name is invalid, or the options
     * supplied are not acceptable to the evaluator
     */
    public static ASEvaluation forName(String evaluatorName,
  				     String [] options) throws Exception {
      return (ASEvaluation)Utils.forName(ASEvaluation.class,
  				       evaluatorName,
  				       options);
    }
  
    /**
     * Creates copies of the current evaluator. Note that this method
     * now uses Serialization to perform a deep copy, so the evaluator
     * object must be fully Serializable. Any currently built model will
     * now be copied as well.
     *
     * @param model an example evaluator to copy
     * @param num the number of evaluator copies to create.
     * @return an array of evaluators.
     * @exception Exception if an error occurs 
     */
    public static ASEvaluation [] makeCopies(ASEvaluation model,
  					 int num) throws Exception {
  
      if (model == null) {
        throw new Exception("No model evaluator set");
      }
      ASEvaluation [] evaluators = new ASEvaluation [num];
      SerializedObject so = new SerializedObject(model);
      for(int i = 0; i < evaluators.length; i++) {
        evaluators[i] = (ASEvaluation) so.getObject();
      }
      return evaluators;
    }
  
    /**
     * Returns the capabilities of this evaluator.
     *
     * @return            the capabilities of this evaluator
     * @see               Capabilities
     */
    public Capabilities getCapabilities() {
      Capabilities result = new Capabilities(this);
      result.enableAll();
      
      return result;
    }
    
    /**
     * Returns the revision string.
     * 
     * @return		the revision
     */
    public String getRevision() {
      return RevisionUtils.extract("$Revision: 6624 $");
    }
    
    /**
     * runs the evaluator with the given commandline options
     * 
     * @param evaluator	the evaluator to run
     * @param options	the commandline options
     */
    public static void runEvaluator(ASEvaluation evaluator, String[] options) {
      try {
        System.out.println(
  	  AttributeSelection.SelectAttributes(evaluator, options));
      }
      catch (Exception e) {
        String msg = e.toString().toLowerCase();
        if (    (msg.indexOf("help requested") == -1)
             && (msg.indexOf("no training file given") == -1) )
          e.printStackTrace();
        System.err.println(e.getMessage());
      }
    }
  }
  