/**
* Remove the last rule in the ruleset as well as it's stats. It might be useful when the last
* rule was added for testing purpose and then the test failed
*/
public void removeLast() {
int last = m_Ruleset.size() - 1;
m_Ruleset.removeElementAt(last);
m_Filtered.removeElementAt(last);
m_SimpleStats.removeElementAt(last);
if (m_Distributions != null) m_Distributions.removeElementAt(last);
}
/**
* Try to reduce the DL of the ruleset by testing removing the rules one by one in reverse order
* and update all the stats
*
* @param expFPRate expected FP/(FP+FN), used in dataDL calculation
* @param checkErr whether check if error rate >= 0.5
*/
public void reduceDL(double expFPRate, boolean checkErr) {
boolean needUpdate = false;
double[] rulesetStat = new double[6];
for (int j = 0; j < m_SimpleStats.size(); j++) {
// Covered stats are cumulative
rulesetStat[0] += ((double[]) m_SimpleStats.elementAt(j))[0];
rulesetStat[2] += ((double[]) m_SimpleStats.elementAt(j))[2];
rulesetStat[4] += ((double[]) m_SimpleStats.elementAt(j))[4];
if (j == m_SimpleStats.size() - 1) { // Last rule
rulesetStat[1] = ((double[]) m_SimpleStats.elementAt(j))[1];
rulesetStat[3] = ((double[]) m_SimpleStats.elementAt(j))[3];
rulesetStat[5] = ((double[]) m_SimpleStats.elementAt(j))[5];
}
}
// Potential
for (int k = m_SimpleStats.size() - 1; k >= 0; k--) {
double[] ruleStat = (double[]) m_SimpleStats.elementAt(k);
// rulesetStat updated
double ifDeleted = potential(k, expFPRate, rulesetStat, ruleStat, checkErr);
if (!Double.isNaN(ifDeleted)) {
/*System.err.println("!!!deleted ("+k+"): save "+ifDeleted
+" | "+rulesetStat[0]
+" | "+rulesetStat[1]
+" | "+rulesetStat[4]
+" | "+rulesetStat[5]);
*/
if (k == (m_SimpleStats.size() - 1)) removeLast();
else {
m_Ruleset.removeElementAt(k);
needUpdate = true;
}
}
}
if (needUpdate) {
m_Filtered = null;
m_SimpleStats = null;
countData();
}
}
/**
* Method that generates all large itemsets with a minimum support, and from these all association
* rules.
*
* @param instances the instances to be used for generating the associations
* @exception Exception if rules can't be built successfully
*/
public void buildAssociations(Instances instances) throws Exception {
int temp = m_premiseCount, exactNumber = m_numRules - 5;
if (instances.checkForStringAttributes()) {
throw new Exception("Can't handle string attributes!");
}
m_instances = instances;
m_instances.setClassIndex(m_instances.numAttributes() - 1);
// prior estimation
m_priorEstimator = new PriorEstimation(m_instances, m_numRandRules, m_numIntervals, false);
m_priors = m_priorEstimator.estimatePrior();
m_midPoints = m_priorEstimator.getMidPoints();
m_Ls = new FastVector();
m_hashtables = new FastVector();
for (int i = 1; i < m_instances.numAttributes(); i++) {
m_bestChanged = false;
// find large item sets
findLargeItemSets(i);
// find association rules (rule generation procedure)
findRulesQuickly();
if (m_bestChanged) {
temp = m_premiseCount;
while (RuleGeneration.expectation(m_premiseCount, m_premiseCount, m_midPoints, m_priors)
<= m_expectation) {
m_premiseCount++;
if (m_premiseCount > m_instances.numInstances()) break;
}
}
if (m_premiseCount > m_instances.numInstances()) {
// Reserve space for variables
m_allTheRules = new FastVector[3];
m_allTheRules[0] = new FastVector();
m_allTheRules[1] = new FastVector();
m_allTheRules[2] = new FastVector();
int k = 0;
while (m_best.size() > 0 && exactNumber > 0) {
m_allTheRules[0].insertElementAt((ItemSet) ((RuleItem) m_best.last()).premise(), k);
m_allTheRules[1].insertElementAt((ItemSet) ((RuleItem) m_best.last()).consequence(), k);
m_allTheRules[2].insertElementAt(new Double(((RuleItem) m_best.last()).accuracy()), k);
boolean remove = m_best.remove(m_best.last());
k++;
exactNumber--;
}
return;
}
if (temp != m_premiseCount && m_Ls.size() > 0) {
FastVector kSets = (FastVector) m_Ls.lastElement();
m_Ls.removeElementAt(m_Ls.size() - 1);
kSets = ItemSet.deleteItemSets(kSets, m_premiseCount, Integer.MAX_VALUE);
m_Ls.addElement(kSets);
}
}
// Reserve space for variables
m_allTheRules = new FastVector[3];
m_allTheRules[0] = new FastVector();
m_allTheRules[1] = new FastVector();
m_allTheRules[2] = new FastVector();
int k = 0;
while (m_best.size() > 0 && exactNumber > 0) {
m_allTheRules[0].insertElementAt((ItemSet) ((RuleItem) m_best.last()).premise(), k);
m_allTheRules[1].insertElementAt((ItemSet) ((RuleItem) m_best.last()).consequence(), k);
m_allTheRules[2].insertElementAt(new Double(((RuleItem) m_best.last()).accuracy()), k);
boolean remove = m_best.remove(m_best.last());
k++;
exactNumber--;
}
}