/*
 *    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.
 */

/*
 *    FURIA.java
 *    Copyright (C) 2008,2009 Jens Christian Huehn
 *    
 *    (based upon) JRip.java
 *    Copyright (C) 2001 Xin Xu, Eibe Frank
 */

package weka.classifiers.rules;

import java.io.Serializable;
import java.util.Enumeration;
import java.util.Random;
import java.util.Vector;

import weka.classifiers.AbstractClassifier;
import weka.core.AdditionalMeasureProducer;
import weka.core.Attribute;
import weka.core.Capabilities;
import weka.core.Copyable;
import weka.core.FastVector;
import weka.core.Instance;
import weka.core.Instances;
import weka.core.Option;
import weka.core.OptionHandler;
import weka.core.SelectedTag;
import weka.core.Tag;
import weka.core.TechnicalInformation;
import weka.core.TechnicalInformationHandler;
import weka.core.Utils;
import weka.core.WeightedInstancesHandler;
import weka.core.Capabilities.Capability;
import weka.core.TechnicalInformation.Field;
import weka.core.TechnicalInformation.Type;

/**
 <!-- globalinfo-start -->
 * FURIA: Fuzzy Unordered Rule Induction Algorithm<br/>
 * <br/>
 * Details please see:<br/>
 * <br/>
 * Jens Christian Huehn, Eyke Huellermeier (2009). FURIA: An Algorithm for Unordered Fuzzy Rule Induction. Data Mining and Knowledge Discovery..<br/>
 * <br/>
 * <p/>
 <!-- globalinfo-end -->
 *
 <!-- technical-bibtex-start -->
 * BibTeX:
 * <pre>
 * &#64;article{Huehn2009,
 *    author = {Jens Christian Huehn and Eyke Huellermeier},
 *    journal = {Data Mining and Knowledge Discovery},
 *    title = {FURIA: An Algorithm for Unordered Fuzzy Rule Induction},
 *    year = {2009}
 * }
 * </pre>
 * <p/>
 <!-- technical-bibtex-end -->
 *
 <!-- options-start -->
 * Valid options are: <p/>
 * 
 * <pre> -F &lt;number of folds&gt;
 *  Set number of folds for REP
 *  One fold is used as pruning set.
 *  (default 3)</pre>
 * 
 * <pre> -N &lt;min. weights&gt;
 *  Set the minimal weights of instances
 *  within a split.
 *  (default 2.0)</pre>
 * 
 * <pre> -O &lt;number of runs&gt;
 *  Set the number of runs of
 *  optimizations. (Default: 2)</pre>
 * 
 * <pre> -D
 *  Set whether turn on the
 *  debug mode (Default: false)</pre>
 * 
 * <pre> -S &lt;seed&gt;
 *  The seed of randomization
 *  (Default: 1)</pre>
 * 
 * <pre> -E
 *  Whether NOT check the error rate&gt;=0.5
 *  in stopping criteria  (default: check)</pre>
 * 
 * <pre> -s
 *  The action performed for uncovered instances.
 *  (default: use stretching)</pre>
 * 
 * <pre> -p
 *  The T-norm used as fuzzy AND-operator.
 *  (default: Product T-norm)</pre>
 * 
 <!-- options-end -->
 *
 * @author Jens Christian H&uuml;hn (huehn@gmx.net)
 * @author Xin Xu (xx5@cs.waikato.ac.nz)
 * @author Eibe Frank (eibe@cs.waikato.ac.nz)
 * @version $Revision: 5964 $
 */
public class FURIA 
  extends AbstractClassifier 
  implements OptionHandler, AdditionalMeasureProducer, WeightedInstancesHandler,
             TechnicalInformationHandler {    

  /** for serialization */
  static final long serialVersionUID = -6589312996832147161L;

  /** The limit of description length surplus in ruleset generation */
  private static double MAX_DL_SURPLUS = 64.0;

  /** The class attribute of the data*/
  private Attribute m_Class; 

  /** The ruleset */
  private FastVector m_Ruleset;

  /** The predicted class distribution */
  private FastVector m_Distributions;

  /** Runs of optimizations */
  private int m_Optimizations = 2;

  /** Random object used in this class */
  private Random m_Random = null;

  /** # of all the possible conditions in a rule */
  private double m_Total = 0;

  /** The seed to perform randomization */
  private long m_Seed = 1;

  /** The number of folds to split data into Grow and Prune for IREP */
  private int m_Folds = 3;

  /** The minimal number of instance weights within a split*/
  private double m_MinNo = 2.0;

  /** Whether in a debug mode */
  private boolean m_Debug = false;

  /** Whether check the error rate >= 0.5 in stopping criteria */
  private boolean m_CheckErr = true;

  /** The class distribution of the training data*/
  private double[] aprioriDistribution;

  /** The RuleStats for the ruleset of each class value */
  private FastVector m_RulesetStats;


  /** What to do if instance is uncovered */
  private int m_uncovAction  = UNCOVACTION_STRETCH;

  /** An uncovered instance is covered using rule stretching. */
  private static final int UNCOVACTION_STRETCH     = 0;

  /** An uncovered instance is classified according to the training data class distribution. */
  private static final int UNCOVACTION_APRIORI     = 1;
  
  /** An uncovered instance is not classified at all. */
  private static final int UNCOVACTION_REJECT      = 2;
  
  /** The tags explaining the uncovered action.  */
  private static final Tag [] TAGS_UNCOVACTION = {
    new Tag(UNCOVACTION_STRETCH, "Apply rule stretching (standard)"),
    new Tag(UNCOVACTION_APRIORI, "Vote for the most frequent class"),
    new Tag(UNCOVACTION_REJECT, "Reject the decision and abstain")
  };


  /** Whether using product T-norm (or else min T-norm) */
  private int m_tNorm  = TNORM_PROD;

  /** The Product T-Norm flag. */
  private static final int TNORM_PROD     = 0;

  /** The Minimum T-Norm flag. */
  private static final int TNORM_MIN     = 1;  

  /** The tags describing the T-norms */
  private static final Tag [] TAGS_TNORM = {
    new Tag(TNORM_PROD, "Product T-Norm (standard)"),
    new Tag(TNORM_MIN, "Minimum T-Norm")
  };


  /**
   * Returns a string describing classifier
   * @return a description suitable for
   * displaying in the explorer/experimenter gui
   */
  public String globalInfo() {

    return "FURIA: Fuzzy Unordered Rule Induction Algorithm\n\n"
    + "Details please see:\n\n"
    + getTechnicalInformation().toString() + "\n\n"; 
  }

  /**
   * 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.
   * 
   * @return the technical information about this class
   */
  public TechnicalInformation getTechnicalInformation() {
    TechnicalInformation 	result;

    result = new TechnicalInformation(Type.ARTICLE);
    result.setValue(Field.AUTHOR, "Jens Christian Huehn and Eyke Huellermeier");
    result.setValue(Field.TITLE, "FURIA: An Algorithm for Unordered Fuzzy Rule Induction");
    result.setValue(Field.YEAR, "2009");
    result.setValue(Field.JOURNAL, "Data Mining and Knowledge Discovery");
    return result;
  }

  /**
   * Returns an enumeration describing the available options
   * Valid options are: <p>
   *  
   * -F number <br>
   * The number of folds for reduced error pruning. One fold is
   * used as the pruning set. (Default: 3) <p>
   * 
   * -N number <br>
   * The minimal weights of instances within a split.
   * (Default: 2) <p>
   *    
   * -O number <br>
   * Set the number of runs of optimizations. (Default: 2)<p>
   *
   * -D <br>
   * Whether turn on the debug mode
   *
   * -S number <br>
   * The seed of randomization used in FURIA.(Default: 1)<p>
   *
   * -E <br>
   * Whether NOT check the error rate >= 0.5 in stopping criteria.
   * (default: check)<p> 
   *
   * -s <br>
   *  The action performed for uncovered instances.
   *  (default: use rule stretching)<p>
   *  
   * -p <br>
   *  The T-Norm used as fuzzy AND-operator.
   *  (default: Product T-Norm)<p>
   *
   * @return an enumeration of all the available options
   */
  public Enumeration listOptions() {
    Vector newVector = new Vector(8);
    newVector.addElement(new Option("\tSet number of folds for REP\n" +
	"\tOne fold is used as pruning set.\n" +
	"\t(default 3)","F", 1, "-F <number of folds>"));

    newVector.addElement(new Option("\tSet the minimal weights of instances\n" +
	"\twithin a split.\n" +
	"\t(default 2.0)","N", 1, "-N <min. weights>"));

    newVector.addElement(new Option("\tSet the number of runs of\n"+
	"\toptimizations. (Default: 2)", "O",
	1,"-O <number of runs>"));

    newVector.addElement(new Option("\tSet whether turn on the\n"+
	"\tdebug mode (Default: false)", "D",
	0,"-D"));

    newVector.addElement(new Option("\tThe seed of randomization\n"+
	"\t(Default: 1)", "S",
	1,"-S <seed>"));

    newVector.addElement(new Option("\tWhether NOT check the error rate>=0.5\n"
	+"\tin stopping criteria "
	+"\t(default: check)", "E", 
	0, "-E")); 

    newVector.addElement(new Option("\tThe action performed for uncovered instances.\n"
	+"\t(default: use stretching)", "s", 
	1, "-s"));

    newVector.addElement(new Option("\tThe T-norm used as fuzzy AND-operator.\n"
	+"\t(default: Product T-norm)", "p", 
	1, "-p"));

    return newVector.elements();
  }

  /**
   * Parses a given list of options. <p/>
   * 
   <!-- options-start -->
   * Valid options are: <p/>
   * 
   * <pre> -F &lt;number of folds&gt;
   *  Set number of folds for REP
   *  One fold is used as pruning set.
   *  (default 3)</pre>
   * 
   * <pre> -N &lt;min. weights&gt;
   *  Set the minimal weights of instances
   *  within a split.
   *  (default 2.0)</pre>
   * 
   * <pre> -O &lt;number of runs&gt;
   *  Set the number of runs of
   *  optimizations. (Default: 2)</pre>
   * 
   * <pre> -D
   *  Set whether turn on the
   *  debug mode (Default: false)</pre>
   * 
   * <pre> -S &lt;seed&gt;
   *  The seed of randomization
   *  (Default: 1)</pre>
   * 
   * <pre> -E
   *  Whether NOT check the error rate&gt;=0.5
   *  in stopping criteria  (default: check)</pre>
   * 
   * <pre> -s
   *  The action performed for uncovered instances.
   *  (default: use stretching)</pre>
   * 
   * <pre> -p
   *  The T-norm used as fuzzy AND-operator.
   *  (default: Product T-norm)</pre>
   * 
   <!-- options-end -->
   *
   * @param options the list of options as an array of strings
   * @throws Exception if an option is not supported
   */
  public void setOptions(String[] options) throws Exception {
    String numFoldsString = Utils.getOption('F', options);
    if (numFoldsString.length() != 0) 
      m_Folds = Integer.parseInt(numFoldsString);
    else 
      m_Folds = 3;   

    String minNoString = Utils.getOption('N', options);
    if (minNoString.length() != 0) 
      m_MinNo = Double.parseDouble(minNoString);
    else 
      m_MinNo = 2.0;

    String seedString = Utils.getOption('S', options);
    if (seedString.length() != 0)
      m_Seed = Long.parseLong(seedString);
    else 
      m_Seed = 1;

    String runString = Utils.getOption('O', options);
    if (runString.length() != 0)
      m_Optimizations = Integer.parseInt(runString);
    else 
      m_Optimizations = 2;

    String tNormString = Utils.getOption('p', options);
    if (tNormString.length() != 0)
      m_tNorm = Integer.parseInt(tNormString);
    else 
      m_tNorm = TNORM_PROD;

    String uncovActionString = Utils.getOption('s', options);
    if (uncovActionString.length() != 0)
      m_uncovAction = Integer.parseInt(uncovActionString);
    else 
      m_uncovAction = UNCOVACTION_STRETCH;

    m_Debug = Utils.getFlag('D', options);

    m_CheckErr = !Utils.getFlag('E', options);
  }

  /**
   * Gets the current settings of the Classifier.
   *
   * @return an array of strings suitable for passing to setOptions
   */
  public String [] getOptions() {

    String [] options = new String [14];
    int current = 0;
    options[current++] = "-F"; options[current++] = "" + m_Folds;
    options[current++] = "-N"; options[current++] = "" + m_MinNo;
    options[current++] = "-O"; options[current++] = "" + m_Optimizations;
    options[current++] = "-S"; options[current++] = "" + m_Seed;
    options[current++] = "-p"; options[current++] = "" + m_tNorm;
    options[current++] = "-s"; options[current++] = "" + m_uncovAction;

    if(m_Debug)
      options[current++] = "-D";

    if(!m_CheckErr)
      options[current++] = "-E";

    while(current < options.length)
      options[current++] = "";

    return options;
  }

  /**
   * Returns an enumeration of the additional measure names
   * @return an enumeration of the measure names
   */
  public Enumeration enumerateMeasures() {
    Vector newVector = new Vector(1);
    newVector.addElement("measureNumRules");
    return newVector.elements();
  }

  /**
   * Returns the value of the named measure
   * @param additionalMeasureName the name of the measure to query for its value
   * @return the value of the named measure
   * @throws IllegalArgumentException if the named measure is not supported
   */
  public double getMeasure(String additionalMeasureName) {
    if (additionalMeasureName.compareToIgnoreCase("measureNumRules") == 0) 
      return m_Ruleset.size();
    else 
      throw new IllegalArgumentException(additionalMeasureName+" not supported (FURIA)");
  }  

  /**
   * Returns the tip text for this property
   * @return tip text for this property suitable for
   * displaying in the explorer/experimenter gui
   */
  public String foldsTipText() {
    return "Determines the amount of data used for pruning. One fold is used for "
    + "pruning, the rest for growing the rules.";
  }

  /**
   * Sets the number of folds to use
   * 
   * @param fold the number of folds
   */
  public void setFolds(int fold) { 
    m_Folds = fold; 
  }

  /**
   * Gets the number of folds
   * 
   * @return the number of folds
   */
  public int getFolds(){ 
    return m_Folds; 
  }

  /**
   * Returns the tip text for this property
   * @return tip text for this property suitable for
   * displaying in the explorer/experimenter gui
   */
  public String minNoTipText() {
    return "The minimum total weight of the instances in a rule.";
  }

  /**
   * Sets the minimum total weight of the instances in a rule
   * 
   * @param m the minimum total weight of the instances in a rule
   */
  public void setMinNo(double m) {
    m_MinNo = m;
  }

  /**
   * Gets the minimum total weight of the instances in a rule
   * 
   * @return the minimum total weight of the instances in a rule
   */
  public double getMinNo(){ 
    return m_MinNo;
  }

  /**
   * Returns the tip text for this property
   * @return tip text for this property suitable for
   * displaying in the explorer/experimenter gui
   */
  public String seedTipText() {
    return "The seed used for randomizing the data.";
  }

  /**
   * Sets the seed value to use in randomizing the data
   * 
   * @param s the new seed value
   */
  public void setSeed(long s) {
    m_Seed = s;
  }

  /**
   * Gets the current seed value to use in randomizing the data
   * 
   * @return the seed value
   */
  public long getSeed(){
    return m_Seed;
  }

  /**
   * Returns the tip text for this property
   * @return tip text for this property suitable for
   * displaying in the explorer/experimenter gui
   */
  public String optimizationsTipText() {
    return "The number of optimization runs.";
  }

  /**
   * Sets the number of optimization runs
   * 
   * @param run the number of optimization runs
   */
  public void setOptimizations(int run) {
    m_Optimizations = run;
  }

  /**
   * Gets the the number of optimization runs
   * 
   * @return the number of optimization runs
   */
  public int getOptimizations() {
    return m_Optimizations;
  }

  /**
   * Returns the tip text for this property
   * @return tip text for this property suitable for
   * displaying in the explorer/experimenter gui
   */
  public String debugTipText() {
    return "Whether debug information is output to the console.";
  }

  /**
   * Sets whether debug information is output to the console
   * 
   * @param d whether debug information is output to the console
   */
  public void setDebug(boolean d) {
    m_Debug = d;
  }

  /**
   * Gets whether debug information is output to the console
   * 
   * @return whether debug information is output to the console
   */
  public boolean getDebug(){
    return m_Debug;
  }

  /**
   * Returns the tip text for this property
   * @return tip text for this property suitable for
   * displaying in the explorer/experimenter gui
   */
  public String checkErrorRateTipText() {
    return "Whether check for error rate >= 1/2 is included" +
    " in stopping criterion.";
  }

  /**
   * Sets whether to check for error rate is in stopping criterion
   * 
   * @param d whether to check for error rate is in stopping criterion
   */
  public void setCheckErrorRate(boolean d) { 
    m_CheckErr = d;
  }

  /**
   * Gets whether to check for error rate is in stopping criterion
   * 
   * @return true if checking for error rate is in stopping criterion
   */
  public boolean getCheckErrorRate(){ 
    return m_CheckErr; 
  } 

  /**
   * Returns the tip text for this property
   * @return tip text for this property suitable for
   * displaying in the explorer/experimenter gui
   */
  public String uncovActionTipText() {
    return "Selet the action that is performed for uncovered instances.";
  }

  /**
   * Gets the action that is performed for uncovered instances.
   * It can be UNCOVACTION_STRETCH, UNCOVACTION_APRIORI or
   * UNCOVACTION_REJECT.
   * @return the current TNorm.
   */
  public SelectedTag getUncovAction() {
    return new SelectedTag(m_uncovAction, TAGS_UNCOVACTION);
  }

  /**
   * Sets the action that is performed for uncovered instances.   
   * It can be UNCOVACTION_STRETCH, UNCOVACTION_APRIORI or
   * UNCOVACTION_REJECT.
   * @param newUncovAction the new action.
   */
  public void setUncovAction(SelectedTag newUncovAction) {
    if (newUncovAction.getTags() == TAGS_UNCOVACTION) {
      m_uncovAction = newUncovAction.getSelectedTag().getID();
    }
  }

  /**
   * Returns the tip text for this property
   * @return tip text for this property suitable for
   * displaying in the explorer/experimenter gui
   */
  public String TNormTipText() {
    return "Choose the T-Norm that is used as fuzzy AND-operator.";
  }

  /**
   * Gets the TNorm used. Will be either TNORM_PROD or TNORM_MIN.
   *
   * @return the current TNorm.
   */
  public SelectedTag getTNorm() {
    return new SelectedTag(m_tNorm, TAGS_TNORM);
  }

  /**
   * Sets the TNorm used. Will be either TNORM_PROD or TNORM_MIN.
   *
   * @param newTNorm the new TNorm.
   */
  public void setTNorm(SelectedTag newTNorm) {
    if (newTNorm.getTags() == TAGS_TNORM) {
      m_tNorm = newTNorm.getSelectedTag().getID();
    }
  }


  /** 
   * Get the ruleset generated by FURIA 
   *
   * @return the ruleset
   */
  public FastVector getRuleset(){ return m_Ruleset; }

  /** 
   * Get the statistics of the ruleset in the given position
   *
   * @param pos the position of the stats, assuming correct
   * @return the statistics of the ruleset in the given position
   */
  public RuleStats getRuleStats(int pos) {
    return (RuleStats)m_RulesetStats.elementAt(pos);
  }

  /** 
   * The single antecedent in the rule, which is composed of an attribute and 
   * the corresponding value.  There are two inherited classes, namely NumericAntd
   * and NominalAntd in which the attributes are numeric and nominal respectively.
   */    
  protected abstract class Antd 
  implements WeightedInstancesHandler, Copyable, Serializable {

    /** The attribute of the antecedent */
    public Attribute att;

    /** The attribute value of the antecedent.  
       For numeric attribute, value is either 0(1st bag) or 1(2nd bag) */
    public double value; 

    /** The maximum infoGain achieved by this antecedent test 
     * in the growing data */
    protected double maxInfoGain;

    /** The accurate rate of this antecedent test on the growing data */
    protected double accuRate;

    /** The coverage of this antecedent in the growing data */
    protected double cover;

    /** The accurate data for this antecedent in the growing data */
    protected double accu;


    /** Confidence / weight of this rule for the rule stretching procedure that
     * is returned when this is the last antecedent of the rule.  */
    double weightOfTheRuleWhenItIsPrunedAfterThisAntecedent = 0;

    /** Confidence / weight of this antecedent.  */
    public double m_confidence = 0.0;

    /** 
     * Constructor
     */
    public Antd(Attribute a){
      att=a;
      value=Double.NaN; 
      maxInfoGain = 0;
      accuRate = Double.NaN;
      cover = Double.NaN;
      accu = Double.NaN;
    }

    /* The abstract members for inheritance */
    public abstract Instances[] splitData(Instances data, double defAcRt, 
	double cla);
    public abstract double covers(Instance inst);
    public abstract String toString();

    /** 
     * Implements Copyable
     * 
     * @return a copy of this object
     */
    public abstract Object copy(); 

    /* Get functions of this antecedent */
    public Attribute getAttr(){ return att; }
    public double getAttrValue(){ return value; }
    public double getMaxInfoGain(){ return maxInfoGain; }
    public double getAccuRate(){ return accuRate; } 
    public double getAccu(){ return accu; } 
    public double getCover(){ return cover; } 
  }

  /** 
   * The antecedent with numeric attribute
   */
  public class 
  NumericAntd extends Antd {

    /** for serialization */
    static final long serialVersionUID = 5699457269983735442L;

    /** The split point for this numeric antecedent */
    public double splitPoint;

    /** The edge point for the fuzzy set of this numeric antecedent */
    public double supportBound; 
    
    /** A flag determining whether this antecedent was successfully fuzzified yet*/
    public boolean fuzzyYet = false;


    /** 
     * Constructor
     */
    public NumericAntd(Attribute a){ 
      super(a);
      splitPoint = Double.NaN;
      supportBound = Double.NaN;
    }    

    /** 
     * Get split point of this numeric antecedent
     * 
     * @return the split point of this numeric antecedent
     */
    public double getSplitPoint(){ 
      return splitPoint;
    }

    /** 
     * Implements Copyable
     * 
     * @return a copy of this object
     */
    public Object copy(){      
      NumericAntd na = new NumericAntd(getAttr());
      na.m_confidence = m_confidence;
      na.value = this.value;
      na.splitPoint = this.splitPoint;
      na.supportBound = this.supportBound;
      na.fuzzyYet = this.fuzzyYet;
      return na;
    }



    /**
     * Implements the splitData function.  
     * This procedure is to split the data into two bags according 
     * to the information gain of the numeric attribute value
     * The maximum infoGain is also calculated.  
     * 
     * @param insts the data to be split
     * @param defAcRt the default accuracy rate for data
     * @param cl the class label to be predicted
     * @return the array of data after split
     */
    public Instances[] splitData(Instances insts, double defAcRt, 
	double cl){
      Instances data = insts;
      int total=data.numInstances();// Total number of instances without 
      // missing value for att

      int split=1;                  // Current split position
      int prev=0;                   // Previous split position
      int finalSplit=split;         // Final split position
      maxInfoGain = 0;
      value = 0;	

      double fstCover=0, sndCover=0, fstAccu=0, sndAccu=0;

      data.sort(att);
      // Find the las instance without missing value 
      for(int x=0; x<data.numInstances(); x++){
	Instance inst = data.instance(x);
	if(inst.isMissing(att)){
	  total = x;
	  break;
	}

	sndCover += inst.weight();
	if(Utils.eq(inst.classValue(), cl))
	  sndAccu += inst.weight();		
      }	    

      if(total == 0) return null; // Data all missing for the attribute
      splitPoint = data.instance(total-1).value(att);	

      for(; split <= total; split++){
	if((split == total) ||
	    (data.instance(split).value(att) > // Can't split within
	    data.instance(prev).value(att))){ // same value	    

	  for(int y=prev; y<split; y++){
	    Instance inst = data.instance(y);
	    fstCover += inst.weight(); 
	    if(Utils.eq(data.instance(y).classValue(), cl)){
	      fstAccu += inst.weight();  // First bag positive# ++
	    }	     		   
	  }

	  double fstAccuRate = (fstAccu+1.0)/(fstCover+1.0),
	  sndAccuRate = (sndAccu+1.0)/(sndCover+1.0);

	  /* Which bag has higher information gain? */
	  boolean isFirst; 
	  double fstInfoGain, sndInfoGain;
	  double accRate, infoGain, coverage, accurate;

	  fstInfoGain = 
	    //Utils.eq(defAcRt, 1.0) ? 
	    //fstAccu/(double)numConds : 
	    fstAccu*(Utils.log2(fstAccuRate)-Utils.log2(defAcRt));

	  sndInfoGain = 
	    //Utils.eq(defAcRt, 1.0) ? 
	    //sndAccu/(double)numConds : 
	    sndAccu*(Utils.log2(sndAccuRate)-Utils.log2(defAcRt));

	  if(fstInfoGain > sndInfoGain){
	    isFirst = true;
	    infoGain = fstInfoGain;
	    accRate = fstAccuRate;
	    accurate = fstAccu;
	    coverage = fstCover;
	  }
	  else{
	    isFirst = false;
	    infoGain = sndInfoGain;
	    accRate = sndAccuRate;
	    accurate = sndAccu;
	    coverage = sndCover;
	  }

	  /* Check whether so far the max infoGain */
	  if(infoGain > maxInfoGain){
	    splitPoint = data.instance(prev).value(att);
	    value = (isFirst) ? 0 : 1;
	    accuRate = accRate;
	    accu = accurate;
	    cover = coverage;
	    maxInfoGain = infoGain;
	    finalSplit = (isFirst) ? split : prev;
	  }

	  for(int y=prev; y<split; y++){
	    Instance inst = data.instance(y);
	    sndCover -= inst.weight(); 
	    if(Utils.eq(data.instance(y).classValue(), cl)){
	      sndAccu -= inst.weight();  // Second bag positive# --
	    }	     		   
	  }		    
	  prev=split;
	}
      }

      /* Split the data */
      Instances[] splitData = new Instances[2];
      splitData[0] = new Instances(data, 0, finalSplit);
      splitData[1] = new Instances(data, finalSplit, total-finalSplit);

      return splitData;
    }


    /**
     * The degree of coverage for the instance given that antecedent
     * 
     * @param inst the instance in question
     * @return the numeric value indicating the membership of the instance 
     *         for this antecedent
     */
    public double covers(Instance inst){
      double isCover=0;
      if(!inst.isMissing(att)){
	if((int)value == 0){ // First bag
	  if(inst.value(att) <= splitPoint)
	    isCover=1;
	  else if(fuzzyYet && (inst.value(att) > splitPoint) && (inst.value(att) < supportBound )) 
	    isCover= 1-((inst.value(att) - splitPoint)/(supportBound-splitPoint));
	}else{ 
	  if(inst.value(att) >= splitPoint) // Second bag
	    isCover=1;
	  else if(fuzzyYet && inst.value(att) < splitPoint && (inst.value(att) > supportBound )) 
	    isCover= 1-((splitPoint - inst.value(att)) /(splitPoint-supportBound));
	}
      }

      return isCover;
    }

    /**
     * Prints this antecedent
     *
     * @return a textual description of this antecedent
     */
    public String toString() {
      if (value == 0){
	if (fuzzyYet){
	  return (att.name() + " in [-inf, -inf, " + Utils.doubleToString(splitPoint, 6) + ", " + Utils.doubleToString(supportBound, 6) + "]");
	}
	return (att.name() + " in [-inf, " + Utils.doubleToString(splitPoint, 6) + "]");
      }else{
	if (fuzzyYet){
	  return (att.name() + " in [" + Utils.doubleToString(supportBound, 6) + ", " + Utils.doubleToString(splitPoint, 6) + ", inf, inf]");
	}
	return (att.name() + " in [" + Utils.doubleToString(splitPoint, 6) + ", inf]");
      }

    }

  }


  /** 
   * The antecedent with nominal attribute
   */
  protected class NominalAntd 
  extends Antd{

    /** for serialization */
    static final long serialVersionUID = -9102297038837585135L;

    /* The parameters of infoGain calculated for each attribute value
     * in the growing data */
    private double[] accurate;
    private double[] coverage;

    /** 
     * Constructor
     */
    public NominalAntd(Attribute a){ 
      super(a);    
      int bag = att.numValues();
      accurate = new double[bag];
      coverage = new double[bag];
    }   

    /** 
     * Implements Copyable
     * 
     * @return a copy of this object
     */
    public Object copy(){
      Antd antec = new NominalAntd(getAttr());
      antec.m_confidence = m_confidence;
      antec.value = this.value;
      return antec;	    
    }

    /**
     * Implements the splitData function.  
     * This procedure is to split the data into bags according 
     * to the nominal attribute value
     * The infoGain for each bag is also calculated.  
     * 
     * @param data the data to be split
     * @param defAcRt the default accuracy rate for data
     * @param cl the class label to be predicted
     * @return the array of data after split
     */
    public Instances[] splitData(Instances data, double defAcRt, 
	double cl){
      int bag = att.numValues();
      Instances[] splitData = new Instances[bag];

      for(int x=0; x<bag; x++){
	splitData[x] = new Instances(data, data.numInstances());
	accurate[x] = 0;
	coverage[x] = 0;
      }

      for(int x=0; x<data.numInstances(); x++){
	Instance inst=data.instance(x);
	if(!inst.isMissing(att)){
	  int v = (int)inst.value(att);
	  splitData[v].add(inst);
	  coverage[v] += inst.weight();
	  if((int)inst.classValue() == (int)cl)
	    accurate[v] += inst.weight();
	}
      }

      for(int x=0; x<bag; x++){
	double t = coverage[x]+1.0;
	double p = accurate[x] + 1.0;		
	double infoGain = 
	  //Utils.eq(defAcRt, 1.0) ? 
	  //accurate[x]/(double)numConds : 
	  accurate[x]*(Utils.log2(p/t)-Utils.log2(defAcRt));

	if(infoGain > maxInfoGain){
	  maxInfoGain = infoGain;
	  cover = coverage[x];
	  accu = accurate[x];
	  accuRate = p/t;
	  value = (double)x;
	}
      }

      return splitData;
    }

    /**
     * Whether the instance is covered by this antecedent
     * 
     * @param inst the instance in question
     * @return the boolean value indicating whether the instance is
     *         covered by this antecedent
     */
    public double covers(Instance inst){
      double isCover=0;
      if(!inst.isMissing(att)){
	if((int)inst.value(att) == (int)value)
	  isCover=1;	    
      }
      return isCover;
    }

    /**
     * Prints this antecedent
     *
     * @return a textual description of this antecedent
     */
    public String toString() {
      return (att.name() + " = " +att.value((int)value));
    } 
  }


  /**
   * This class implements a single rule that predicts specified class.  
   *
   * A rule consists of antecedents "AND"ed together and the consequent 
   * (class value) for the classification.  
   * In this class, the Information Gain (p*[log(p/t) - log(P/T)]) is used to
   * select an antecedent and Reduced Error Prunning (REP) with the metric
   * of accuracy rate p/(p+n) or (TP+TN)/(P+N) is used to prune the rule. 
   */    
  public class RipperRule 
  extends Rule{

    /** for serialization */
    static final long serialVersionUID = -2410020717305262952L;

    /** The internal representation of the class label to be predicted */
    double m_Consequent = -1;	

    /** The vector of antecedents of this rule*/
    public FastVector m_Antds = null;

    /** Constructor */
    public RipperRule(){    
      m_Antds = new FastVector();	
    }

    /**
     * Sets the internal representation of the class label to be predicted
     * 
     * @param cl the internal representation of the class label to be predicted
     */
    public void setConsequent(double cl) {
      m_Consequent = cl; 
    }

    /**
     * Gets the internal representation of the class label to be predicted
     * 
     * @return the internal representation of the class label to be predicted
     */
    public double getConsequent() { 
      return m_Consequent; 
    }

    /**
     * Get a shallow copy of this rule
     *
     * @return the copy
     */
    public Object copy(){
      RipperRule copy = new RipperRule();
      copy.setConsequent(getConsequent());
      copy.m_Antds = (FastVector)this.m_Antds.copyElements();
      return copy;
    }



    /**
     * The degree of coverage instance covered by this rule
     * 
     * @param datum the instance in question
     * @return the degree to which the instance 
     *         is covered by this rule
     */
    public double coverageDegree(Instance datum){
      double coverage = 1;

      for(int i=0; i<m_Antds.size(); i++){
	Antd antd = (Antd)m_Antds.elementAt(i);
	if(m_tNorm == TNORM_PROD){
	  // Product T-Norm
	  if (antd instanceof NumericAntd)
	    coverage *= ((NumericAntd)antd).covers(datum);
	  else
	    coverage *= antd.covers(datum);
	}else{
	  // Min T-Norm
	  if (antd instanceof NumericAntd)
	    coverage = Math.min(coverage, ((NumericAntd)antd).covers(datum));
	  else
	    coverage = Math.min(coverage, antd.covers(datum));
	}

      }

      return coverage;
    } 

    /**
     * Whether the instance covered by this rule
     * 
     * @param datum the instance in question
     * @return the boolean value indicating whether the instance 
     *         is covered by this rule
     */
    public boolean covers(Instance datum){ 
      if (coverageDegree(datum) == 0){
	return false;
      }else{
	return true;
      }
    }       

    /**
     * Whether this rule has antecedents, i.e. whether it is a default rule
     * 
     * @return the boolean value indicating whether the rule has antecedents
     */
    public boolean hasAntds(){
      if (m_Antds == null)
	return false;
      else
	return (m_Antds.size() > 0);
    }      

    /** 
     * the number of antecedents of the rule
     *
     * @return the size of this rule
     */
    public double size(){ return (double)m_Antds.size(); }		


    /**
     * Private function to compute default number of accurate instances
     * in the specified data for the consequent of the rule
     * 
     * @param data the data in question
     * @return the default accuracy number
     */
    private double computeDefAccu(Instances data){ 
      double defAccu=0;
      for(int i=0; i<data.numInstances(); i++){
	Instance inst = data.instance(i);
	if((int)inst.classValue() == (int)m_Consequent)
	  defAccu += inst.weight();
      }
      return defAccu;
    }


    /**
     * Build one rule using the growing data
     *
     * @param data the growing data used to build the rule
     * @throws Exception if the consequent is not set yet
     */    
    public void grow(Instances data) throws Exception {
      if(m_Consequent == -1)
	throw new Exception(" Consequent not set yet.");

      Instances growData = data;	         
      double sumOfWeights = growData.sumOfWeights();
      if(!Utils.gr(sumOfWeights, 0.0))
	return;

      /* Compute the default accurate rate of the growing data */
      double defAccu = computeDefAccu(growData);
      double defAcRt = (defAccu+1.0)/(sumOfWeights+1.0); 

      /* Keep the record of which attributes have already been used*/    
      boolean[] used=new boolean [growData.numAttributes()];
      for (int k=0; k<used.length; k++)
	used[k]=false;
      int numUnused=used.length;

      // If there are already antecedents existing
      for(int j=0; j < m_Antds.size(); j++){
	Antd antdj = (Antd)m_Antds.elementAt(j);
	if(!antdj.getAttr().isNumeric()){ 
	  used[antdj.getAttr().index()]=true;
	  numUnused--;
	} 
      }	    

      double maxInfoGain;	    
      while (Utils.gr(growData.numInstances(), 0.0) && 
	  (numUnused > 0) 
	  && Utils.sm(defAcRt, 1.0)
      ){   

	// We require that infoGain be positive
	/*if(numAntds == originalSize)
	  maxInfoGain = 0.0; // At least one condition allowed
	  else
	  maxInfoGain = Utils.eq(defAcRt, 1.0) ? 
	  defAccu/(double)numAntds : 0.0; */
	maxInfoGain = 0.0; 

	/* Build a list of antecedents */
	Antd oneAntd=null;
	Instances coverData = null;
	Enumeration enumAttr=growData.enumerateAttributes();	      

	/* Build one condition based on all attributes not used yet*/
	while (enumAttr.hasMoreElements()){
	  Attribute att= (Attribute)(enumAttr.nextElement());

	  if(m_Debug)
	    System.err.println("\nOne condition: size = " 
		+ growData.sumOfWeights());

	  Antd antd =null;	
	  if(att.isNumeric())
	    antd = new NumericAntd(att);
	  else
	    antd = new NominalAntd(att);

	  if(!used[att.index()]){
	    /* Compute the best information gain for each attribute,
	       it's stored in the antecedent formed by this attribute.
	       This procedure returns the data covered by the antecedent*/
	    Instances coveredData = computeInfoGain(growData, defAcRt,
		antd);
	    if(coveredData != null){
	      double infoGain = antd.getMaxInfoGain();      
	      if(m_Debug)
		System.err.println("Test of \'"+antd.toString()+
		    "\': infoGain = "+
		    infoGain + " | Accuracy = " +
		    antd.getAccuRate()+
		    "="+antd.getAccu()
		    +"/"+antd.getCover()+
		    " def. accuracy: "+defAcRt);

	      if(infoGain > maxInfoGain){         
		oneAntd=antd;
		coverData = coveredData;  
		maxInfoGain = infoGain;
	      }		    
	    }
	  }
	}

	if(oneAntd == null) break; // Cannot find antds		
	if(Utils.sm(oneAntd.getAccu(), m_MinNo)) break;// Too low coverage

	//Numeric attributes can be used more than once
	if(!oneAntd.getAttr().isNumeric()){ 
	  used[oneAntd.getAttr().index()]=true;
	  numUnused--;
	}

	m_Antds.addElement(oneAntd);


	growData = coverData;// Grow data size is shrinking 	
	defAcRt = oneAntd.getAccuRate();
      }
    }


    /** 
     * Compute the best information gain for the specified antecedent
     *  
     * @param instances the data based on which the infoGain is computed
     * @param defAcRt the default accuracy rate of data
     * @param antd the specific antecedent
     * @return the data covered by the antecedent
     */
    private Instances computeInfoGain(Instances instances, double defAcRt, 
	Antd antd){
      Instances data = instances;

      /* Split the data into bags.
	 The information gain of each bag is also calculated in this procedure */
      Instances[] splitData = antd.splitData(data, defAcRt, 
	  m_Consequent); 

      /* Get the bag of data to be used for next antecedents */
      if(splitData != null)
	return splitData[(int)antd.getAttrValue()];
      else return null;
    }

    /**
     * Prune all the possible final sequences of the rule using the 
     * pruning data.  The measure used to prune the rule is based on
     * flag given.
     *
     * @param pruneData the pruning data used to prune the rule
     * @param useWhole flag to indicate whether use the error rate of
     *                 the whole pruning data instead of the data covered
     */    
    public void prune(Instances pruneData, boolean useWhole){
      Instances data = pruneData;

      double total = data.sumOfWeights();
      if(!Utils.gr(total, 0.0))
	return;

      /* The default accurate # and rate on pruning data */
      double defAccu=computeDefAccu(data);

      if(m_Debug)	
	System.err.println("Pruning with " + defAccu + 
	    " positive data out of " + total +
	" instances");	

      int size=m_Antds.size();
      if(size == 0) return; // Default rule before pruning

      double[] worthRt = new double[size];
      double[] coverage = new double[size];
      double[] worthValue = new double[size];
      for(int w=0; w<size; w++){
	worthRt[w]=coverage[w]=worthValue[w]=0.0;
      }

      /* Calculate accuracy parameters for all the antecedents in this rule */
      double tn = 0.0; // True negative if useWhole
      for(int x=0; x<size; x++){
	Antd antd=(Antd)m_Antds.elementAt(x);
	Instances newData = data;
	data = new Instances(newData, 0); // Make data empty

	for(int y=0; y<newData.numInstances(); y++){
	  Instance ins=newData.instance(y);

	  if(antd.covers(ins)>0){   // Covered by this antecedent
	    coverage[x] += ins.weight();
	    data.add(ins);                 // Add to data for further pruning
	    if((int)ins.classValue() == (int)m_Consequent) // Accurate prediction
	      worthValue[x] += ins.weight();
	  }
	  else if(useWhole){ // Not covered
	    if((int)ins.classValue() != (int)m_Consequent)
	      tn += ins.weight();
	  }			
	}

	if(useWhole){
	  worthValue[x] += tn;
	  worthRt[x] = worthValue[x] / total;
	}
	else // Note if coverage is 0, accuracy is 0.5
	  worthRt[x] = (worthValue[x]+1.0)/(coverage[x]+2.0);
      }

      double maxValue = (defAccu+1.0)/(total+2.0);
      int maxIndex = -1;
      for(int i=0; i<worthValue.length; i++){
	if(m_Debug){
	  double denom = useWhole ? total : coverage[i];
	  System.err.println(i+"(useAccuray? "+!useWhole+"): "
	      + worthRt[i] + 
	      "="+worthValue[i]+
	      "/"+denom);
	}
	if(worthRt[i] > maxValue){ // Prefer to the 
	  maxValue = worthRt[i]; // shorter rule
	  maxIndex = i;
	}
      }

      if (maxIndex==-1) return;

      /* Prune the antecedents according to the accuracy parameters */
      for(int z=size-1;z>maxIndex;z--)
	m_Antds.removeElementAt(z);       
    }

    /**
     * Prints this rule
     *
     * @param classAttr the class attribute in the data
     * @return a textual description of this rule
     */
    public String toString(Attribute classAttr) {
      StringBuffer text =  new StringBuffer();
      if(m_Antds.size() > 0){
	for(int j=0; j< (m_Antds.size()-1); j++)
	  text.append("(" + ((Antd)(m_Antds.elementAt(j))).toString()+ ") and ");
	text.append("("+((Antd)(m_Antds.lastElement())).toString() + ")");
      }
      text.append(" => " + classAttr.name() +
	  "=" + classAttr.value((int)m_Consequent));

      return text.toString();
    }

    /**
     * The fuzzification procedure
     * @param data training data
     * @param allWeightsAreOne flag whether all instances have weight 1. If this is the case branch-and-bound is possible for speed-up.
     */
    public void fuzzify(Instances data, boolean allWeightsAreOne){
      // Determine whether there are numeric antecedents that can be fuzzified.
      if (m_Antds == null) return;
      int numNumericAntds = 0;
      for (int i = 0; i < m_Antds.size(); i++){
	if (m_Antds.elementAt(i) instanceof NumericAntd)
	  numNumericAntds++;
      }
      if (numNumericAntds == 0)
	return;

      double maxPurity = Double.NEGATIVE_INFINITY;
      boolean[] finishedAntecedents = new boolean[m_Antds.size()];
      int numFinishedAntecedents = 0;

      // Loop until all antecdents have been fuzzified
      while (numFinishedAntecedents<m_Antds.size()){	
	double maxPurityOfAllAntecedents = Double.NEGATIVE_INFINITY;
	int bestAntecedentsIndex = -1;
	double bestSupportBoundForAllAntecedents = Double.NaN;

	Instances relevantData = new Instances(data,0);
	for (int j = 0; j < m_Antds.size(); j++){
	  if(finishedAntecedents[j]) continue; 

	  relevantData = new Instances (data);
	  /*
	   * Remove instances which are not relevant, because they are not covered
	   * by the _other_ antecedents.
	   */
	  for (int k = 0; k < m_Antds.size(); k++){
	    if (k==j) continue;
	    Antd exclusionAntd = ((Antd)m_Antds.elementAt(k));
	    for (int y = 0; y < relevantData.numInstances(); y++){
	      if (exclusionAntd.covers(relevantData.instance(y)) == 0){
		relevantData.delete(y--);
	      }
	    }
	  }

	  // test whether this antecedent is numeric and whether there is data for making it fuzzy
	  if (relevantData.attribute(((Antd)m_Antds.elementAt(j)).att.index()).isNumeric() && relevantData.numInstances()>0){
	    // Get a working copy of this antecedent
	    NumericAntd currentAntd = (NumericAntd) ((NumericAntd) m_Antds.elementAt(j)).copy();
	    currentAntd.fuzzyYet=true;

	    relevantData.deleteWithMissing(currentAntd.att.index());

	    double sumOfWeights = relevantData.sumOfWeights();
	    if(!Utils.gr(sumOfWeights, 0.0))
	      return;

	    relevantData.sort(currentAntd.att.index());

	    double maxPurityForThisAntecedent = 0;
	    double bestFoundSupportBound = Double.NaN;

	    double lastAccu = 0;
	    double lastCover = 0;
	    // Test all possible edge points
	    if (currentAntd.value == 0){
	      for (int k = 1; k < relevantData.numInstances(); k++){
		// break the loop if there is no gain (only works when all instances have weight 1)
		if ((lastAccu+(relevantData.numInstances()-k-1))/(lastCover+(relevantData.numInstances()-k-1)) < maxPurityForThisAntecedent && allWeightsAreOne){
		  break;
		}

		// Bag 1 
		if (currentAntd.splitPoint < relevantData.instance(k).value(currentAntd.att.index())                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  
		    && relevantData.instance(k).value(currentAntd.att.index()) != relevantData.instance(k-1).value(currentAntd.att.index())){                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              
		  currentAntd.supportBound = relevantData.instance(k).value(currentAntd.att.index());                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                

		  // Calculate the purity of this fuzzification
		  double[] accuArray = new double[relevantData.numInstances()];                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   
		  double[] coverArray =  new double[relevantData.numInstances()];                       
		  for (int i = 0; i < relevantData.numInstances(); i++){                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          
		    coverArray[i] = relevantData.instance(i).weight();                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            
		    double coverValue = currentAntd.covers(relevantData.instance(i));
		    if (coverArray[i] >= coverValue*relevantData.instance(i).weight()){                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           
		      coverArray[i] = coverValue*relevantData.instance(i).weight();                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               
		      if (relevantData.instance(i).classValue() == m_Consequent){                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
			accuArray[i] = coverValue*relevantData.instance(i).weight();                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              
		      }                 
		    }                   
		  }                     

		  // Test whether this fuzzification is the best one for this antecedent.
		  // Keep it if this is the case.
		  double purity = (Utils.sum(accuArray)) / (Utils.sum(coverArray));                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             
		  if (purity >= maxPurityForThisAntecedent){                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      
		    maxPurityForThisAntecedent =purity;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           
		    bestFoundSupportBound =  currentAntd.supportBound;     
		  }           
		  lastAccu = Utils.sum(accuArray);
		  lastCover = Utils.sum(coverArray);
		}                           
	      }                             
	    }else{                          
	      for (int k = relevantData.numInstances()-2; k >=0; k--){
		// break the loop if there is no gain (only works when all instances have weight 1)
		if ((lastAccu+(k))/(lastCover+(k)) < maxPurityForThisAntecedent && allWeightsAreOne){
		  break;
		}

		//Bag 2                     
		if (currentAntd.splitPoint > relevantData.instance(k).value(currentAntd.att.index())                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  
		    && relevantData.instance(k).value(currentAntd.att.index()) != relevantData.instance(k+1).value(currentAntd.att.index())){                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              
		  currentAntd.supportBound = relevantData.instance(k).value(currentAntd.att.index());                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                

		  // Calculate the purity of this fuzzification
		  double[] accuArray = new double[relevantData.numInstances()];
		  double[] coverArray =  new double[relevantData.numInstances()];
		  for (int i = 0; i < relevantData.numInstances(); i++){
		    coverArray[i] = relevantData.instance(i).weight();
		    double coverValue = currentAntd.covers(relevantData.instance(i));
		    if (coverArray[i] >= coverValue*relevantData.instance(i).weight()){                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           
		      coverArray[i] = coverValue*relevantData.instance(i).weight();                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               
		      if (relevantData.instance(i).classValue() == m_Consequent){                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
			accuArray[i] = coverValue*relevantData.instance(i).weight();                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              
		      }                 
		    }                   
		  }                     

		  // Test whether this fuzzification is the best one for this antecedent.
		  // Keep it if this is the case.
		  double purity = (Utils.sum(accuArray)) / (Utils.sum(coverArray));                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            
		  if (purity >= maxPurityForThisAntecedent){                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      
		    maxPurityForThisAntecedent =purity;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           
		    bestFoundSupportBound =  currentAntd.supportBound;    
		  }
		  lastAccu = Utils.sum(accuArray);
		  lastCover = Utils.sum(coverArray);
		}                           
	      }                             

	    }             

	    // Test whether the best fuzzification for this antecedent is the best one of all
	    // antecedents considered so far.
	    // Keep it if this is the case.
	    if (maxPurityForThisAntecedent>maxPurityOfAllAntecedents){
	      bestAntecedentsIndex = j;
	      bestSupportBoundForAllAntecedents = bestFoundSupportBound;
	      maxPurityOfAllAntecedents = maxPurityForThisAntecedent;
	    }
	  }else{
	    // Deal with a nominal antecedent. 
	    // Since there is no fuzzification it is already finished.
	    finishedAntecedents[j] = true;
	    numFinishedAntecedents++;
	    continue;
	  }
	}

	// Make the fuzzification step for the current antecedent real. 
	if (maxPurity <= maxPurityOfAllAntecedents){
	  if (Double.isNaN(bestSupportBoundForAllAntecedents)){
	    ((NumericAntd)m_Antds.elementAt(bestAntecedentsIndex)).supportBound =  ((NumericAntd)m_Antds.elementAt(bestAntecedentsIndex)).splitPoint;
	  }else{
	    ((NumericAntd)m_Antds.elementAt(bestAntecedentsIndex)).supportBound = bestSupportBoundForAllAntecedents;
	    ((NumericAntd)m_Antds.elementAt(bestAntecedentsIndex)).fuzzyYet = true;
	  }  
	  maxPurity = maxPurityOfAllAntecedents;
	}
	finishedAntecedents[bestAntecedentsIndex] = true;
	numFinishedAntecedents++;
      }

    }

    /**
     * Calculation of the rule weights / confidences for all beginning rule stumps.
     * @param data The training data
     */
    public void calculateConfidences(Instances data) {
      RipperRule tempRule = (RipperRule) this.copy();

      while(tempRule.hasAntds()){
	double acc = 0;
	double cov = 0;
	for (int i = 0; i < data.numInstances(); i++){
	  double membershipValue = tempRule.coverageDegree(data.instance(i)) * data.instance(i).weight();
	  cov += membershipValue;
	  if (m_Consequent == data.instance(i).classValue()){
	    acc += membershipValue;
	  }
	}

	// m-estimate
	double m = 2.0;
	((Antd)this.m_Antds.elementAt((int)tempRule.size()-1)).m_confidence = 
	  (acc+m*(aprioriDistribution[(int)m_Consequent]/
	      Utils.sum(aprioriDistribution))) / (cov+m);
	tempRule.m_Antds.removeElementAt(tempRule.m_Antds.size()-1);
      }
    }


    /**
     * Get the rule confidence.
     * @return rule confidence / weight
     */
    public double getConfidence(){
      if (!hasAntds()) 
	return Double.NaN;
      return ((Antd)m_Antds.lastElement()).m_confidence;
    }

    /**
     * 
     */
    public String getRevision() {
      return "1.0";
    }

  }

  /**
   * Returns default capabilities of the classifier.
   *
   * @return      the capabilities of this classifier
   */
  public Capabilities getCapabilities() {
    Capabilities result = super.getCapabilities();
    result.disableAll();

    // attributes
    result.enable(Capability.NOMINAL_ATTRIBUTES);
    result.enable(Capability.NUMERIC_ATTRIBUTES);
    result.enable(Capability.DATE_ATTRIBUTES);
    result.enable(Capability.MISSING_VALUES);

    // class
    result.enable(Capability.NOMINAL_CLASS);
    result.enable(Capability.MISSING_CLASS_VALUES);

    // instances
    result.setMinimumNumberInstances(m_Folds);

    return result;
  }

  /**
   * Builds the FURIA rule-based model 
   *
   * @param instances the training data
   * @throws Exception if classifier can't be built successfully
   */
  public void buildClassifier(Instances instances) throws Exception {  
    // can classifier handle the data?
    getCapabilities().testWithFail(instances);

    // remove instances with missing class
    instances = new Instances(instances);
    instances.deleteWithMissingClass();

    // Learn the apriori distribution for later
    aprioriDistribution = new double[instances.classAttribute().numValues()];
    boolean allWeightsAreOne = true;
    for (int i = 0 ; i < instances.numInstances(); i++){
      aprioriDistribution[(int)instances.instance(i).classValue()]+=instances.instance(i).weight();
      if (allWeightsAreOne && instances.instance(i).weight() != 1.0){
	allWeightsAreOne = false;
	break;
      }
    }


    m_Random = instances.getRandomNumberGenerator(m_Seed); 
    m_Total = RuleStats.numAllConditions(instances);
    if(m_Debug)
      System.err.println("Number of all possible conditions = "+m_Total);

    Instances data = new Instances(instances);

    m_Class = data.classAttribute();	
    m_Ruleset = new FastVector();
    m_RulesetStats = new FastVector();
    m_Distributions = new FastVector();


    // Learn a rule set for each single class
    oneClass:	
      for(int y=0; y < data.numClasses(); y++){ // For each class	      

	double classIndex = (double)y;
	if(m_Debug){
	  int ci = (int)classIndex;
	  System.err.println("\n\nClass "+m_Class.value(ci)+"("+ci+"): "
	      + aprioriDistribution[y] + "instances\n"+
	  "=====================================\n");
	}

	if(Utils.eq(aprioriDistribution[y],0.0)) // No data for this class
	  continue oneClass;		

	// The expected FP/err is the proportion of the class    
	double expFPRate = (aprioriDistribution[y] / Utils.sum(aprioriDistribution));


	double classYWeights = 0, totalWeights = 0;
	for(int j=0; j < data.numInstances(); j++){
	  Instance datum = data.instance(j);
	  totalWeights += datum.weight();
	  if((int)datum.classValue() == y){
	    classYWeights += datum.weight();
	  }	          
	}	

	// DL of default rule, no theory DL, only data DL
	double defDL;
	if(classYWeights > 0)
	  defDL = RuleStats.dataDL(expFPRate, 
	      0.0,
	      totalWeights,
	      0.0,
	      classYWeights);	    
	else
	  continue oneClass; // Subsumed by previous rules



	if(Double.isNaN(defDL) || Double.isInfinite(defDL))
	  throw new Exception("Should never happen: "+
	  "defDL NaN or infinite!");
	if(m_Debug)
	  System.err.println("The default DL = "+defDL);

	rulesetForOneClass(expFPRate, data, classIndex, defDL);
      }

    // Remove redundant antecedents
    for(int z=0; z < m_Ruleset.size(); z++){
      RipperRule rule = (RipperRule)m_Ruleset.elementAt(z);
      for(int j = 0; j < rule.m_Antds.size(); j++){
	Antd outerAntd = (Antd)rule.m_Antds.elementAt(j);
	for (int k = j+1; k < rule.m_Antds.size(); k++){
	  Antd innerAntd = (Antd)rule.m_Antds.elementAt(k);  
	  if (outerAntd.att.index() == innerAntd.att.index() && outerAntd.value==innerAntd.value){
	    rule.m_Antds.setElementAt(rule.m_Antds.elementAt(k), j);
	    rule.m_Antds.removeElementAt(k--);
	  }
	}
      }
    } 


    // Fuzzify all rules
    for(int z=0; z < m_RulesetStats.size(); z++){
      RuleStats oneClass = (RuleStats)m_RulesetStats.elementAt(z);
      for(int xyz=0; xyz < oneClass.getRulesetSize(); xyz++){
	RipperRule rule = (RipperRule)((FastVector)oneClass.getRuleset()).elementAt(xyz);

	// do the fuzzification for all known antecedents 
	rule.fuzzify(data, allWeightsAreOne);

	double[] classDist = oneClass.getDistributions(xyz);
	// Check for sum=0, because otherwise it does not work
	if (Utils.sum(classDist)>0) Utils.normalize(classDist);
	if(classDist != null)
	  m_Distributions.addElement(classDist);
      }	
    }


    // if there was some problem during fuzzification, set the support bound
    // to the trivial fuzzification position
    for(int z=0; z < m_Ruleset.size(); z++){
      RipperRule rule = (RipperRule)m_Ruleset.elementAt(z);
      for(int j = 0; j < rule.m_Antds.size(); j++){
	Antd antd = (Antd)rule.m_Antds.elementAt(j);
	if (antd instanceof NumericAntd) {
	  NumericAntd numAntd = (NumericAntd) antd;


	  if (!numAntd.fuzzyYet){
	    for (int i = 0; i < data.numInstances(); i++){
	      if ((numAntd.value == 1 && 
		  numAntd.splitPoint > data.instance(i).value(numAntd.att.index()) &&
		  (numAntd.supportBound < data.instance(i).value(numAntd.att.index()) ||
		      !numAntd.fuzzyYet)
	      )
	      ||
	      (numAntd.value == 0 && 
		  numAntd.splitPoint < data.instance(i).value(numAntd.att.index()) &&
		  (numAntd.supportBound > data.instance(i).value(numAntd.att.index()) ||
		      !numAntd.fuzzyYet)
	      )
	      ){
		numAntd.supportBound = data.instance(i).value(numAntd.att.index());
		numAntd.fuzzyYet = true;
	      }
	    }

	  }	  
	}
      }
    }

    //Determine confidences
    for(int z=0; z < m_Ruleset.size(); z++){
      RipperRule rule = (RipperRule)m_Ruleset.elementAt(z);
      rule.calculateConfidences(data);
    }
  }

  /**
   * Classify the test instance with the rule learner and provide
   * the class distributions 
   *
   * @param datum the instance to be classified
   * @return the distribution
   * @throws Exception 
   */

  public double[] distributionForInstance(Instance datum) throws Exception{ 
    //test for multiple overlap of rules
    double[] rulesCoveringForEachClass = new double[datum.numClasses()];
    for(int i=0; i < m_Ruleset.size(); i++){
      RipperRule rule = (RipperRule)m_Ruleset.elementAt(i);

      /* In case that one class does not contain any instances (e.g. in UCI-dataset glass), 
       * a default rule assigns all instances to the other class. Such a rule may be ignored here.
       */
      if (!rule.hasAntds()) 
	continue;


      // Calculate the maximum degree of coverage
      if(rule.covers(datum)){
	rulesCoveringForEachClass[(int)rule.m_Consequent] += rule.coverageDegree(datum) * rule.getConfidence();
      }

    }


    // If no rule covered the example, then maybe start the rule stretching
    if (Utils.sum(rulesCoveringForEachClass)==0){

      // If rule stretching is not allowed,  
      // return either the apriori prediction
      if (m_uncovAction == UNCOVACTION_APRIORI){
	rulesCoveringForEachClass = aprioriDistribution;
	if (Utils.sum(rulesCoveringForEachClass)>0)
	  Utils.normalize(rulesCoveringForEachClass);
	return rulesCoveringForEachClass;
      }
      // or abstain from that decision at all.
      if (m_uncovAction == UNCOVACTION_REJECT)
	return rulesCoveringForEachClass;

      // Copy the ruleset as backup
      FastVector origRuleset = (FastVector) m_Ruleset.copyElements();

      // Find for every rule the first antecedent that does not
      // cover the given instance. 
      rulesCoveringForEachClass = new double[rulesCoveringForEachClass.length];
      for(int i=0; i < m_Ruleset.size(); i++){
	RipperRule rule = (RipperRule)m_Ruleset.elementAt(i);
	double numAntdsBefore = rule.m_Antds.size();

	int firstAntdToDelete = Integer.MAX_VALUE;
	for (int j = 0; j < rule.m_Antds.size(); j++){
	  if (((Antd)rule.m_Antds.elementAt(j)).covers(datum)==0){
	    firstAntdToDelete = j;
	    break;
	  }
	}

	// Prune antecedent such that it covers the instance
	for (int j = firstAntdToDelete; j < rule.m_Antds.size(); j++){
	  rule.m_Antds.removeElementAt(j--);
	}
	double numAntdsAfter = rule.m_Antds.size();

	// Empty rules shall not vote here
	if (!rule.hasAntds())
	  continue;

	// Calculate the maximum degree of coverage and weight the rule
	// by its confidence and the fraction of antecedents left after
	// rule stretching
	double secondWeight = (numAntdsAfter+1)/(numAntdsBefore+2) ;
	if (rule.getConfidence() *secondWeight*rule.coverageDegree(datum) >= rulesCoveringForEachClass[(int)rule.getConsequent()]){
	  rulesCoveringForEachClass[(int)rule.getConsequent()] = rule.getConfidence()*secondWeight*rule.coverageDegree(datum);
	}
      }

      // Reestablish original ruleset
      m_Ruleset = origRuleset;
    }

    //check for conflicts
    double[] maxClasses = new double[rulesCoveringForEachClass.length];
    for (int i = 0; i < rulesCoveringForEachClass.length; i++){
      if (rulesCoveringForEachClass[Utils.maxIndex(rulesCoveringForEachClass)] ==
	rulesCoveringForEachClass[i] && rulesCoveringForEachClass[i]>0)
	maxClasses[i] = 1;
    }

    //If there is a conflict, resolve it using the apriori distribution
    if (Utils.sum(maxClasses)>0){
      for (int i = 0; i < maxClasses.length; i++){
	if (maxClasses[i] > 0 && aprioriDistribution[i] != rulesCoveringForEachClass[Utils.maxIndex(rulesCoveringForEachClass)])
	  rulesCoveringForEachClass[i] -= 0.00001;
      }
    }

    // If no stretched rule was able to cover the instance,
    // then fall back to the apriori distribution
    if (Utils.sum(rulesCoveringForEachClass)==0){
      rulesCoveringForEachClass = aprioriDistribution;
    }


    if (Utils.sum(rulesCoveringForEachClass)>0)
      Utils.normalize(rulesCoveringForEachClass);

    return rulesCoveringForEachClass;

  }


  /** Build a ruleset for the given class according to the given data
   *
   * @param expFPRate the expected FP/(FP+FN) used in DL calculation
   * @param data the given data
   * @param classIndex the given class index
   * @param defDL the default DL in the data
   * @throws Exception if the ruleset can be built properly
   */
  protected Instances rulesetForOneClass(double expFPRate, 
      Instances data, 
      double classIndex,
      double defDL)
  throws Exception {

    Instances newData = data, growData, pruneData;  	
    boolean stop = false;
    FastVector ruleset = new FastVector();		

    double dl = defDL, minDL = defDL;
    RuleStats rstats = null;
    double[] rst;

    // Check whether data have positive examples
    boolean defHasPositive = true; // No longer used
    boolean hasPositive = defHasPositive;

    /********************** Building stage ***********************/	
    if(m_Debug)
      System.err.println("\n*** Building stage ***");


    while((!stop) && hasPositive){ // Generate new rules until
      // stopping criteria met
      RipperRule oneRule;

      oneRule = new RipperRule();
      oneRule.setConsequent(classIndex);  // Must set first
      if(m_Debug)
	System.err.println("\nNo pruning: growing a rule ...");
      oneRule.grow(newData);             // Build the rule
      if(m_Debug)
	System.err.println("No pruning: one rule found:\n"+
	    oneRule.toString(m_Class));


      // Compute the DL of this ruleset
      if(rstats == null){ // First rule
	rstats = new RuleStats();
	rstats.setNumAllConds(m_Total);
	rstats.setData(newData);
      }

      rstats.addAndUpdate(oneRule);		    
      int last = rstats.getRuleset().size()-1; // Index of last rule
      dl += rstats.relativeDL(last, expFPRate, m_CheckErr);

      if(Double.isNaN(dl) || Double.isInfinite(dl))
	throw new Exception("Should never happen: dl in "+
	"building stage NaN or infinite!");
      if(m_Debug)
	System.err.println("Before optimization("+last+
	    "): the dl = "+dl+" | best: "+minDL);

      if(dl < minDL)
	minDL = dl;  // The best dl so far	

      rst = rstats.getSimpleStats(last);	    
      if(m_Debug)
	System.err.println("The rule covers: "+rst[0]+
	    " | pos = " + rst[2] + 
	    " | neg = " + rst[4]+
	    "\nThe rule doesn't cover: "+rst[1]+
	    " | pos = " + rst[5]);

      stop = checkStop(rst, minDL, dl);

      if(!stop){	  		
	ruleset.addElement(oneRule);          // Accepted 
	newData = rstats.getFiltered(last)[1];// Data not covered
	hasPositive = Utils.gr(rst[5], 0.0);  // Positives remaining?
	if(m_Debug)
	  System.err.println("One rule added: has positive? "
	      +hasPositive);
      }
      else{
	if(m_Debug)
	  System.err.println("Quit rule");
	rstats.removeLast(); // Remove last to be re-used
      }
    }// while !stop


    /******************** Optimization stage *******************/

    RuleStats finalRulesetStat = null; 
    for(int z=0; z < m_Optimizations; z++){
      if(m_Debug)
	System.err.println("\n*** Optimization: run #"
	    +z+" ***");

      newData = data;		    
      finalRulesetStat = new RuleStats();
      finalRulesetStat.setData(newData);
      finalRulesetStat.setNumAllConds(m_Total);
      int position=0;
      stop = false;
      boolean isResidual = false;	    
      hasPositive = defHasPositive;		    
      dl = minDL = defDL;

      oneRule:    
	while(!stop && hasPositive){			

	  isResidual = (position>=ruleset.size()); // Cover residual positive examples  
	  // Re-do shuffling and stratification    
	  //newData.randomize(m_Random);	
	  newData = RuleStats.stratify(newData, m_Folds, m_Random);
	  Instances[] part = RuleStats.partition(newData, m_Folds);
	  growData=part[0];
	  pruneData=part[1];
	  //growData=newData.trainCV(m_Folds, m_Folds-1);
	  //pruneData=newData.testCV(m_Folds, m_Folds-1);	   
	  RipperRule finalRule;

	  if(m_Debug)
	    System.err.println("\nRule #"+position +
		"| isResidual?" + isResidual+
		"| data size: "+newData.sumOfWeights());

	  if(isResidual){
	    RipperRule newRule = new RipperRule();   
	    newRule.setConsequent(classIndex);
	    if(m_Debug)
	      System.err.println("\nGrowing and pruning"+
	      " a new rule ...");
	    newRule.grow(newData);
	    finalRule = newRule;
	    if(m_Debug)
	      System.err.println("\nNew rule found: "+
		  newRule.toString(m_Class));
	  }
	  else{
	    RipperRule oldRule = (RipperRule)ruleset.elementAt(position);
	    boolean covers = false;
	    // Test coverage of the next old rule
	    for(int i=0; i<newData.numInstances(); i++)
	      if(oldRule.covers(newData.instance(i))){
		covers = true;
		break;
	      }

	    if(!covers){// Null coverage, no variants can be generated
	      finalRulesetStat.addAndUpdate(oldRule);
	      position++;
	      continue oneRule;
	    }  

	    // 2 variants 
	    if(m_Debug)
	      System.err.println("\nGrowing and pruning"+
	      " Replace ..."); 
	    RipperRule replace = new RipperRule();   
	    replace.setConsequent(classIndex);
	    replace.grow(growData);

	    // Remove the pruning data covered by the following
	    // rules, then simply compute the error rate of the
	    // current rule to prune it.  According to Ripper,
	    // it's equivalent to computing the error of the 
	    // whole ruleset -- is it true?
	    pruneData = RuleStats.rmCoveredBySuccessives(pruneData,ruleset, position);      	
	    replace.prune(pruneData, true);

	    if(m_Debug)
	      System.err.println("\nGrowing and pruning"+
	      " Revision ..."); 
	    RipperRule revision = (RipperRule)oldRule.copy(); 

	    // For revision, first rm the data covered by the old rule
	    Instances newGrowData = new Instances(growData, 0);
	    for(int b=0; b<growData.numInstances(); b++){
	      Instance inst = growData.instance(b);
	      if(revision.covers(inst))
		newGrowData.add(inst);
	    }
	    revision.grow(newGrowData);	      
	    revision.prune(pruneData, true);

	    double[][] prevRuleStats = new double[position][6];
	    for(int c=0; c < position; c++)
	      prevRuleStats[c] = finalRulesetStat.getSimpleStats(c);

	    // Now compare the relative DL of variants
	    FastVector tempRules = (FastVector)ruleset.copyElements();
	    tempRules.setElementAt(replace, position);

	    RuleStats repStat = new RuleStats(data, tempRules);
	    repStat.setNumAllConds(m_Total);
	    repStat.countData(position, newData, prevRuleStats);
	    //repStat.countData();
	    rst = repStat.getSimpleStats(position);	    
	    if(m_Debug)
	      System.err.println("Replace rule covers: "+rst[0]+
		  " | pos = " + rst[2] + 
		  " | neg = " + rst[4]+
		  "\nThe rule doesn't cover: "+rst[1]+
		  " | pos = " + rst[5]);

	    double repDL = repStat.relativeDL(position, expFPRate,
		m_CheckErr);

	    if(m_Debug)
	      System.err.println("\nReplace: "+
		  replace.toString(m_Class)
		  +" |dl = "+repDL); 

	    if(Double.isNaN(repDL) || Double.isInfinite(repDL))
	      throw new Exception("Should never happen: repDL"+
		  "in optmz. stage NaN or "+
	      "infinite!");

	    tempRules.setElementAt(revision, position);
	    RuleStats revStat = new RuleStats(data, tempRules);
	    revStat.setNumAllConds(m_Total);
	    revStat.countData(position, newData, prevRuleStats);
	    //revStat.countData();
	    double revDL = revStat.relativeDL(position, expFPRate,
		m_CheckErr);

	    if(m_Debug)
	      System.err.println("Revision: "
		  + revision.toString(m_Class)
		  +" |dl = "+revDL);

	    if(Double.isNaN(revDL) || Double.isInfinite(revDL))
	      throw new Exception("Should never happen: revDL"+
		  "in optmz. stage NaN or "+
	      "infinite!");

	    rstats = new RuleStats(data, ruleset);
	    rstats.setNumAllConds(m_Total);
	    rstats.countData(position, newData, prevRuleStats);
	    //rstats.countData();
	    double oldDL = rstats.relativeDL(position, expFPRate,
		m_CheckErr);

	    if(Double.isNaN(oldDL) || Double.isInfinite(oldDL))
	      throw new Exception("Should never happen: oldDL"+
		  "in optmz. stage NaN or "+
	      "infinite!");
	    if(m_Debug)
	      System.err.println("Old rule: "+
		  oldRule.toString(m_Class)
		  +" |dl = "+oldDL); 

	    if(m_Debug)
	      System.err.println("\nrepDL: "+repDL+ 
		  "\nrevDL: "+revDL+
		  "\noldDL: "+oldDL);

	    if((oldDL <= revDL) && (oldDL <= repDL))
	      finalRule = oldRule; // Old the best
	    else if(revDL <= repDL)
	      finalRule = revision; // Revision the best
	    else
	      finalRule = replace; // Replace the best  
	  }		

	  finalRulesetStat.addAndUpdate(finalRule);  	 
	  rst = finalRulesetStat.getSimpleStats(position);

	  if(isResidual){	
	    dl += finalRulesetStat.relativeDL(position, 
		expFPRate,
		m_CheckErr);

	    if(m_Debug)
	      System.err.println("After optimization: the dl"
		  +"="+dl+" | best: "+minDL);

	    if(dl < minDL)
	      minDL = dl;  // The best dl so far

	    stop = checkStop(rst, minDL, dl);
	    if(!stop)
	      ruleset.addElement(finalRule); // Accepted 
	    else{
	      finalRulesetStat.removeLast(); // Remove last to be re-used
	      position--;
	    }
	  }
	  else
	    ruleset.setElementAt(finalRule, position); // Accepted 

	  if(m_Debug){
	    System.err.println("The rule covers: "+rst[0]+
		" | pos = " + rst[2] + 
		" | neg = " + rst[4]+
		"\nThe rule doesn't cover: "+rst[1]+
		" | pos = " + rst[5]);		
	    System.err.println("\nRuleset so far: ");
	    for(int x=0; x<ruleset.size(); x++)
	      System.err.println(x+": "+((RipperRule)ruleset.elementAt(x)).toString(m_Class));
	    System.err.println();
	  }

	  //Data not covered	
	  if(finalRulesetStat.getRulesetSize() > 0)// If any rules	
	    newData = finalRulesetStat.getFiltered(position)[1]; 
	  hasPositive = Utils.gr(rst[5], 0.0); //Positives remaining? 
	  position++;
	} // while !stop && hasPositive

      if(ruleset.size() > (position+1)){ // Hasn't gone through yet
	for(int k=position+1; k<ruleset.size(); k++)
	  finalRulesetStat.addAndUpdate((Rule)ruleset.elementAt(k));
      }
      if(m_Debug)
	System.err.println("\nDeleting rules to decrease"+
	" DL of the whole ruleset ..."); 
      finalRulesetStat.reduceDL(expFPRate, m_CheckErr);

      if(m_Debug){
	int del = ruleset.size() -
	finalRulesetStat.getRulesetSize(); 
	System.err.println(del+" rules are deleted"+
	" after DL reduction procedure");
      }
      ruleset = finalRulesetStat.getRuleset();
      rstats = finalRulesetStat;	      	    

    } // For each run of optimization

    // Concatenate the ruleset for this class to the whole ruleset
    if(m_Debug){
      System.err.println("\nFinal ruleset: ");
      for(int x=0; x<ruleset.size(); x++)
	System.err.println(x+": "+((RipperRule)ruleset.elementAt(x)).toString(m_Class));
      System.err.println();
    }


    m_Ruleset.appendElements(ruleset);
    m_RulesetStats.addElement(rstats);

    return null;
  }   

  /**
   * Check whether the stopping criterion meets
   *
   * @param rst the statistic of the ruleset
   * @param minDL the min description length so far
   * @param dl the current description length of the ruleset
   * @return true if stop criterion meets, false otherwise
   */
  private boolean checkStop(double[] rst, double minDL, double dl){


    if(dl > minDL+MAX_DL_SURPLUS){
      if(m_Debug)
	System.err.println("DL too large: "+dl+" | "+minDL);
      return true;
    }
    else 
      if(!Utils.gr(rst[2], 0.0)){// Covered positives
	if(m_Debug)
	  System.err.println("Too few positives.");
	return true;
      }	
      else if((rst[4]/rst[0]) >= 0.5){// Err rate
	if(m_CheckErr){
	  if(m_Debug)
	    System.err.println("Error too large: "+
		rst[4] + "/" + rst[0]);
	  return  true;
	}
	else
	  return false;
      }		
      else{// Not stops
	if(m_Debug)
	  System.err.println("Continue.");
	return  false;
      }				
  }

  /**
   * Prints the all the rules of the rule learner.
   *
   * @return a textual description of the classifier
   */
  public String toString() {
    if (m_Ruleset == null) 
      return "FURIA: No model built yet.";

    StringBuffer sb = new StringBuffer("FURIA rules:\n"+
    "===========\n\n"); 
    for(int j=0; j<m_RulesetStats.size(); j++){
      RuleStats rs = (RuleStats)m_RulesetStats.elementAt(j);
      FastVector rules = rs.getRuleset();
      for(int k=0; k<rules.size(); k++){
	sb.append(((RipperRule)rules.elementAt(k)).toString(m_Class)
	    + " (CF = " + Math.round(100.0*((RipperRule)rules.elementAt(k)).getConfidence())/100.0 +")\n");
      }			    
    }
    if(m_Debug){
      System.err.println("Inside m_Ruleset");
      for(int i=0; i<m_Ruleset.size(); i++)
	System.err.println(((RipperRule)m_Ruleset.elementAt(i)).toString(m_Class));
    }
    sb.append("\nNumber of Rules : " 
	+ m_Ruleset.size() + "\n");




    return sb.toString();
  }

  /**
   * Main method.
   *
   * @param args the options for the classifier
   * @throws Exception 
   */
  public static void main(String[] args) throws Exception {
    runClassifier(new FURIA(), args);
  }

  /**
   * 
   */
  public String getRevision() {
    return "$Revision: 5964 $";
  }
}