/**
* 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;
}
/**
* 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);
}
/**
* 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;
}
/**
* 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;
}
