@Override
public void doWork() throws OperatorException {
ExampleSet originalExampleSet = exampleSetInput.getData(ExampleSet.class);
double fraction = getParameterAsDouble(PARAMETER_FRACTION);
if (fraction < 0 || fraction > 1.0)
throw new UserError(
this,
207,
new Object[] {
fraction, "fraction", "Cannot use fractions of less than 0.0 or more than 1.0"
});
SplittedExampleSet splitted =
new SplittedExampleSet(
originalExampleSet,
fraction,
getParameterAsInt(PARAMETER_SAMPLING_TYPE),
getParameterAsBoolean(RandomGenerator.PARAMETER_USE_LOCAL_RANDOM_SEED),
getParameterAsInt(RandomGenerator.PARAMETER_LOCAL_RANDOM_SEED));
splitted.selectSingleSubset(0);
exampleSubsetInnerSource.deliver(splitted);
getSubprocess(0).execute();
modelOutput.deliver(modelInnerSink.getData(IOObject.class));
}
private RuleModel createNumericalRuleModel(ExampleSet trainingSet, Attribute attribute) {
RuleModel model = new RuleModel(trainingSet);
// split by best attribute
int oldSize = -1;
while ((trainingSet.size() > 0) && (trainingSet.size() != oldSize)) {
ExampleSet exampleSet = (ExampleSet) trainingSet.clone();
Split bestSplit = splitter.getBestSplit(exampleSet, attribute, null);
double bestSplitValue = bestSplit.getSplitPoint();
if (!Double.isNaN(bestSplitValue)) {
SplittedExampleSet splittedSet =
SplittedExampleSet.splitByAttribute(exampleSet, attribute, bestSplitValue);
Attribute label = splittedSet.getAttributes().getLabel();
splittedSet.selectSingleSubset(0);
SplitCondition condition = new LessEqualsSplitCondition(attribute, bestSplitValue);
splittedSet.recalculateAttributeStatistics(label);
int labelValue = (int) splittedSet.getStatistics(label, Statistics.MODE);
String labelName = label.getMapping().mapIndex(labelValue);
Rule rule = new Rule(labelName, condition);
int[] frequencies = new int[label.getMapping().size()];
int counter = 0;
for (String value : label.getMapping().getValues())
frequencies[counter++] = (int) splittedSet.getStatistics(label, Statistics.COUNT, value);
rule.setFrequencies(frequencies);
model.addRule(rule);
oldSize = trainingSet.size();
trainingSet = rule.removeCovered(trainingSet);
} else {
break;
}
}
// add default rule if some examples were not yet covered
if (trainingSet.size() > 0) {
Attribute label = trainingSet.getAttributes().getLabel();
trainingSet.recalculateAttributeStatistics(label);
int index = (int) trainingSet.getStatistics(label, Statistics.MODE);
String defaultLabel = label.getMapping().mapIndex(index);
Rule defaultRule = new Rule(defaultLabel);
int[] frequencies = new int[label.getMapping().size()];
int counter = 0;
for (String value : label.getMapping().getValues())
frequencies[counter++] = (int) (trainingSet.getStatistics(label, Statistics.COUNT, value));
defaultRule.setFrequencies(frequencies);
model.addRule(defaultRule);
}
return model;
}
@Override
public void estimatePerformance(ExampleSet inputSet) throws OperatorException {
// split by attribute
Attribute batchAttribute = inputSet.getAttributes().getSpecial(Attributes.BATCH_NAME);
if (batchAttribute == null) {
throw new UserError(this, 113, Attributes.BATCH_NAME);
}
SplittedExampleSet splittedES = SplittedExampleSet.splitByAttribute(inputSet, batchAttribute);
// start crossvalidation
for (iteration = 0; iteration < splittedES.getNumberOfSubsets(); iteration++) {
splittedES.selectAllSubsetsBut(iteration);
learn(splittedES);
splittedES.selectSingleSubset(iteration);
evaluate(splittedES);
inApplyLoop();
}
// end crossvalidation
}
private RuleModel createNominalRuleModel(ExampleSet exampleSet, Attribute attribute) {
RuleModel model = new RuleModel(exampleSet);
SplittedExampleSet splittedSet = SplittedExampleSet.splitByAttribute(exampleSet, attribute);
Attribute label = splittedSet.getAttributes().getLabel();
for (int i = 0; i < splittedSet.getNumberOfSubsets(); i++) {
splittedSet.selectSingleSubset(i);
splittedSet.recalculateAttributeStatistics(label);
SplitCondition term =
new NominalSplitCondition(attribute, attribute.getMapping().mapIndex(i));
int labelValue = (int) splittedSet.getStatistics(label, Statistics.MODE);
String labelName = label.getMapping().mapIndex(labelValue);
Rule rule = new Rule(labelName, term);
int[] frequencies = new int[label.getMapping().size()];
int counter = 0;
for (String value : label.getMapping().getValues())
frequencies[counter++] = (int) splittedSet.getStatistics(label, Statistics.COUNT, value);
rule.setFrequencies(frequencies);
model.addRule(rule);
}
return model;
}
@Override
public ExampleSet apply(ExampleSet exampleSet) throws OperatorException {
// creating kernel and settings from Parameters
int k = Math.min(100, exampleSet.getAttributes().size() * 2);
int size = exampleSet.size();
switch (getParameterAsInt(PARAMETER_SAMPLE)) {
case SAMPLE_ABSOLUTE:
size = getParameterAsInt(PARAMETER_SAMPLE_SIZE);
break;
case SAMPLE_RELATIVE:
size = (int) Math.round(exampleSet.size() * getParameterAsDouble(PARAMETER_SAMPLE_RATIO));
break;
}
DistanceMeasure distanceMeasure = new EuclideanDistance();
distanceMeasure.init(exampleSet);
// finding farthest and nearest example to mean Vector
double[] meanVector = getMeanVector(exampleSet);
Candidate min = new Candidate(meanVector, Double.POSITIVE_INFINITY, 0);
Candidate max = new Candidate(meanVector, Double.NEGATIVE_INFINITY, 0);
int i = 0;
for (Example example : exampleSet) {
double[] exampleValues = getExampleValues(example);
Candidate current =
new Candidate(
exampleValues,
Math.abs(distanceMeasure.calculateDistance(meanVector, exampleValues)),
i);
if (current.compareTo(min) < 0) {
min = current;
}
if (current.compareTo(max) > 0) {
max = current;
}
i++;
}
ArrayList<Candidate> recentlySelected = new ArrayList<Candidate>(10);
int[] partition = new int[exampleSet.size()];
int numberOfSelectedExamples = 2;
recentlySelected.add(min);
recentlySelected.add(max);
partition[min.getExampleIndex()] = 1;
partition[max.getExampleIndex()] = 1;
double[] minimalDistances = new double[exampleSet.size()];
Arrays.fill(minimalDistances, Double.POSITIVE_INFINITY);
// running now through examples, checking for smallest distance to one of the candidates
while (numberOfSelectedExamples < size) {
TreeSet<Candidate> candidates = new TreeSet<Candidate>();
i = 0;
// check distance only for candidates recently selected.
for (Example example : exampleSet) {
// if example not has been selected allready
if (partition[i] == 0) {
double[] exampleValues = getExampleValues(example);
for (Candidate candidate : recentlySelected) {
minimalDistances[i] =
Math.min(
minimalDistances[i],
Math.abs(
distanceMeasure.calculateDistance(exampleValues, candidate.getValues())));
}
Candidate newCandidate = new Candidate(exampleValues, minimalDistances[i], i);
candidates.add(newCandidate);
if (candidates.size() > k) {
Iterator<Candidate> iterator = candidates.iterator();
iterator.next();
iterator.remove();
}
}
i++;
}
// clearing recently selected since now new ones will be selected
recentlySelected.clear();
// now running in descending order through candidates and adding to selected
// IM: descendingIterator() is not available in Java versions less than 6 !!!
// IM: Bad workaround for now by adding all candidates into a list and using a listIterator()
// and hasPrevious...
/*
Iterator<Candidate> descendingIterator = candidates.descendingIterator();
while (descendingIterator.hasNext() && numberOfSelectedExamples < desiredNumber) {
Candidate candidate = descendingIterator.next();
*/
List<Candidate> reverseCandidateList = new LinkedList<Candidate>();
Iterator<Candidate> it = candidates.iterator();
while (it.hasNext()) {
reverseCandidateList.add(it.next());
}
ListIterator<Candidate> lit =
reverseCandidateList.listIterator(reverseCandidateList.size() - 1);
while (lit.hasPrevious()) {
Candidate candidate = lit.previous();
// IM: end of workaround
boolean existSmallerDistance = false;
Iterator<Candidate> addedIterator = recentlySelected.iterator();
// test if a distance to recently selected is smaller than previously calculated minimal
// distance
// if one exists: This is not selected
while (addedIterator.hasNext()) {
double distance =
Math.abs(
distanceMeasure.calculateDistance(
addedIterator.next().getValues(), candidate.getValues()));
existSmallerDistance = existSmallerDistance || distance < candidate.getDistance();
}
if (!existSmallerDistance) {
recentlySelected.add(candidate);
partition[candidate.getExampleIndex()] = 1;
numberOfSelectedExamples++;
} else break;
}
}
// building new exampleSet containing only Examples with indices in selectedExamples
SplittedExampleSet sample = new SplittedExampleSet(exampleSet, new Partition(partition, 2));
sample.selectSingleSubset(1);
return sample;
}