Ejemplo n.º 1
0
  /**
   * Places all rules that satisfy the given record in a CMAR rule linked list pointed at by
   * startCMARrulelist field, in the order that rules are presented.
   *
   * <p>Used in Weighted Chi-Squared classification (CMAR) algorithm.
   *
   * @param linkref The reference to the start of the existing list of rules.
   * @param itemset the record to be classified.
   */
  private void obtainallRulesForRecord(RuleNodeCMAR linkRef, short[] itemSet) {
    RuleNodeCMAR newStartRef = null;
    RuleNodeCMAR markerRef = null;

    // Loop through linked list of existing rules
    while (linkRef != null) {
      // If rule satisfies record add to new rule list
      if (isSubset(linkRef.antecedent, itemSet)) {
        RuleNodeCMAR newNode =
            new RuleNodeCMAR(
                linkRef.antecedent,
                linkRef.consequent,
                linkRef.supportForRule,
                linkRef.suppAntecedent,
                linkRef.suppConsequent,
                linkRef.confidenceForRule);
        if (newStartRef == null) newStartRef = newNode;
        else markerRef.next = newNode;

        markerRef = newNode;
        /*if (newStartRef==null) newStartRef=linkRef;
        else markerRef.next=linkRef;
        markerRef=linkRef; */
      }
      linkRef = linkRef.next;
    }

    // Set rule list
    startCMARrulelist = newStartRef;
  }
Ejemplo n.º 2
0
  /**
   * Groups rules contained in a linked list of rules pointed at by <TT>startCMARrulelist</TT>
   * according to their consequent.
   *
   * @return an array of rule groups.
   */
  private RuleNodeCMAR[] groupRules() {
    // Initialise rule groups data structure
    RuleNodeCMAR[] ruleGroups = new RuleNodeCMAR[numClasses];
    for (int index = 0; index < ruleGroups.length; index++) ruleGroups[index] = null;
    // Loop through rule list
    RuleNodeCMAR linkRef = startCMARrulelist;
    while (linkRef != null) {
      // Identify index for consequent
      int index = numOneItemSets - linkRef.consequent[0];
      // Add to rule group
      RuleNodeCMAR ruleCopy =
          new RuleNodeCMAR(
              linkRef.antecedent,
              linkRef.consequent,
              linkRef.supportForRule,
              linkRef.suppAntecedent,
              linkRef.suppConsequent,
              linkRef.confidenceForRule);
      ruleCopy.next = ruleGroups[index];
      ruleGroups[index] = ruleCopy;
      // Increment link reference
      linkRef = linkRef.next;
    }

    // Return
    return (ruleGroups);
  }
Ejemplo n.º 3
0
  /**
   * Prunes the current CMAR list of rules according to the "cover" principle.
   *
   * @param trainingSet the input data set.
   */
  protected void pruneUsingCover(short[][] trainingSet) {
    // Initialise cover array
    int[] cover = new int[trainingSet.length];

    // Define rule list references
    RuleNodeCMAR newStartRef = null;
    RuleNodeCMAR markerRef = null;
    RuleNodeCMAR linkRef = startCMARrulelist;

    // Loop through rule list
    while (linkRef != null) {
      // If no more training records end
      if (emptyDataSet(trainingSet)) break;
      // Set cover flag to false, will be set to true of a rule matches
      // a record.
      boolean coverFlag = false;
      // Loop through training set
      for (int index = 0; index < trainingSet.length; index++) {
        // If record satisfies a rule increment cover element for
        // record and set cover flag to true to indicate that rule
        // is required by at least one record
        if (isSubset(linkRef.antecedent, trainingSet[index])) {
          cover[index]++;
          coverFlag = true;
        }
      }

      // If current rule is required by at least one record (cover flag
      // set to true) add to new rule list
      if (coverFlag) {
        if (newStartRef == null) newStartRef = linkRef;
        else markerRef.next = linkRef;

        markerRef = linkRef;
        linkRef = linkRef.next;
        markerRef.next = null;
      } else linkRef = linkRef.next;

      // Remove records from training set if adequately covered
      for (int index = 0; index < cover.length; index++) {
        if (cover[index] > MIN_COVER) trainingSet[index] = null;
      }
    }

    // Set rule list
    startCMARrulelist = newStartRef;
  }
Ejemplo n.º 4
0
  /**
   * Inserts an (association/classification) rule into the linkedlist of rules pointed at by
   * <TT>startRulelist</TT>.
   *
   * <p>List is ordered according to "CMAR" ranking.
   *
   * @param antecedent the antecedent (LHS) of the rule.
   * @param consequent the consequent (RHS) of the rule.
   * @param supportForAntecedent the associated support for the antecedent.
   * @param supportForConsequent the associated support for the consequent.
   * @param supportForRule the associated support value.
   * @param confidenceForRule the associated confidence value.
   */
  protected void insertRinRlistCMARranking(
      short[] antecedent,
      short[] consequent,
      double supportForAntecedent,
      double supportForConsequent,
      double supportForRule,
      double confidenceForRule) {
    // Test rule using Chi-Squared testing
    if (!testRuleUsingChiSquaredTesting(
        supportForAntecedent, supportForConsequent, supportForRule, numRows)) return;

    // Create new node
    RuleNodeCMAR newNode =
        new RuleNodeCMAR(
            antecedent,
            consequent,
            supportForRule,
            supportForAntecedent,
            supportForConsequent,
            confidenceForRule);

    // Empty rule list situation
    if (startCMARrulelist == null) {
      startCMARrulelist = newNode;
      return;
    }

    // Check if more general rule with higher ranking exists.
    if (moreGeneralRuleExists(newNode)) return;

    // Add new node to start
    if (ruleIsCMARgreater(newNode, startCMARrulelist)) {
      newNode.next = startCMARrulelist;
      startCMARrulelist = newNode;
      return;
    }

    // Add new node to middle
    RuleNodeCMAR markerNode = startCMARrulelist;
    RuleNodeCMAR linkRuleNode = startCMARrulelist.next;
    while (linkRuleNode != null) {
      if (ruleIsCMARgreater(newNode, linkRuleNode)) {
        markerNode.next = newNode;
        newNode.next = linkRuleNode;
        return;
      }
      markerNode = linkRuleNode;
      linkRuleNode = linkRuleNode.next;
    }

    // Add new node to end
    markerNode.next = newNode;
  }