/** Performs the DBSCAN algorithm on the given database. */
public Clustering<Model> run(Relation<O> relation) {
final int size = relation.size();
if (size < minpts) {
Clustering<Model> result = new Clustering<>("DBSCAN Clustering", "dbscan-clustering");
result.addToplevelCluster(
new Cluster<Model>(relation.getDBIDs(), true, ClusterModel.CLUSTER));
return result;
}
RangeQuery<O> rangeQuery = QueryUtil.getRangeQuery(relation, getDistanceFunction());
resultList = new ArrayList<>();
noise = DBIDUtil.newHashSet();
runDBSCAN(relation, rangeQuery);
double averagen = ncounter / (double) relation.size();
LOG.statistics(new DoubleStatistic(DBSCAN.class.getName() + ".average-neighbors", averagen));
if (averagen < 1 + 0.1 * (minpts - 1)) {
LOG.warning("There are very few neighbors found. Epsilon may be too small.");
}
if (averagen > 100 * minpts) {
LOG.warning("There are very many neighbors found. Epsilon may be too large.");
}
Clustering<Model> result = new Clustering<>("DBSCAN Clustering", "dbscan-clustering");
for (ModifiableDBIDs res : resultList) {
result.addToplevelCluster(new Cluster<Model>(res, ClusterModel.CLUSTER));
}
result.addToplevelCluster(new Cluster<Model>(noise, true, ClusterModel.CLUSTER));
return result;
}
/**
* Handles a DataStoreEvent with the specified type. If the current event type is not equal to the
* specified type, the events accumulated up to now will be fired first.
*
* <p>The new event will be aggregated and fired on demand if {@link #accumulateDataStoreEvents}
* is set, otherwise all registered <code>DataStoreListener</code> will be notified immediately
* that the content of the database has been changed.
*
* @param objects the objects that have been changed, i.e. inserted, deleted or updated
*/
private void fireObjectsChanged(DBIDs objects, Type type) {
// flush first
if (currentDataStoreEventType != null && !currentDataStoreEventType.equals(type)) {
flushDataStoreEvents();
}
if (accumulateDataStoreEvents) {
if (this.dataStoreObjects == null) {
this.dataStoreObjects = DBIDUtil.newHashSet();
}
this.dataStoreObjects.addDBIDs(objects);
currentDataStoreEventType = type;
return;
}
// Execute immediately:
DataStoreEvent e;
switch (type) {
case INSERT:
e = DataStoreEvent.insertionEvent(objects);
break;
case REMOVE:
e = DataStoreEvent.removalEvent(objects);
break;
case UPDATE:
e = DataStoreEvent.updateEvent(objects);
break;
default:
return;
}
for (int i = dataListenerList.size(); --i >= 0; ) {
dataListenerList.get(i).contentChanged(e);
}
}
/**
* Utility method to create a subspace cluster from a list of DBIDs and the relevant attributes.
*
* @param relation to compute a centroid.
* @param C the cluster points.
* @param D the relevant dimensions.
* @return an object representing the subspace cluster.
*/
private Cluster<SubspaceModel> makeCluster(Relation<V> relation, DBIDs C, long[] D) {
DBIDs ids = DBIDUtil.newHashSet(C); // copy, also to lose distance values!
Cluster<SubspaceModel> cluster = new Cluster<>(ids);
cluster.setModel(
new SubspaceModel(new Subspace(D), Centroid.make(relation, ids).getArrayRef()));
return cluster;
}
@Override
public Clustering<KMeansModel> run(Database database, Relation<V> relation) {
if (relation.size() <= 0) {
return new Clustering<>("k-Means Clustering", "kmeans-clustering");
}
// Choose initial means
if (LOG.isStatistics()) {
LOG.statistics(new StringStatistic(KEY + ".initialization", initializer.toString()));
}
double[][] means = initializer.chooseInitialMeans(database, relation, k, getDistanceFunction());
// Setup cluster assignment store
List<ModifiableDBIDs> clusters = new ArrayList<>();
for (int i = 0; i < k; i++) {
clusters.add(DBIDUtil.newHashSet((int) (relation.size() * 2. / k)));
}
WritableIntegerDataStore assignment =
DataStoreUtil.makeIntegerStorage(
relation.getDBIDs(), DataStoreFactory.HINT_TEMP | DataStoreFactory.HINT_HOT, -1);
double[] varsum = new double[k];
IndefiniteProgress prog =
LOG.isVerbose() ? new IndefiniteProgress("K-Means iteration", LOG) : null;
DoubleStatistic varstat =
LOG.isStatistics()
? new DoubleStatistic(this.getClass().getName() + ".variance-sum")
: null;
int iteration = 0;
for (; maxiter <= 0 || iteration < maxiter; iteration++) {
LOG.incrementProcessed(prog);
boolean changed = assignToNearestCluster(relation, means, clusters, assignment, varsum);
logVarstat(varstat, varsum);
// Stop if no cluster assignment changed.
if (!changed) {
break;
}
// Recompute means.
means = means(clusters, means, relation);
}
LOG.setCompleted(prog);
if (LOG.isStatistics()) {
LOG.statistics(new LongStatistic(KEY + ".iterations", iteration));
}
// Wrap result
Clustering<KMeansModel> result = new Clustering<>("k-Means Clustering", "kmeans-clustering");
for (int i = 0; i < clusters.size(); i++) {
DBIDs ids = clusters.get(i);
if (ids.size() == 0) {
continue;
}
KMeansModel model = new KMeansModel(means[i], varsum[i]);
result.addToplevelCluster(new Cluster<>(ids, model));
}
return result;
}
@Override
public Clustering<BiclusterWithInversionsModel> biclustering() {
double[][] mat = RelationUtil.relationAsMatrix(relation, rowIDs);
BiclusterCandidate cand = new BiclusterCandidate(getRowDim(), getColDim());
Clustering<BiclusterWithInversionsModel> result =
new Clustering<>("Cheng-and-Church", "Cheng and Church Biclustering");
ModifiableDBIDs noise = DBIDUtil.newHashSet(relation.getDBIDs());
FiniteProgress prog = LOG.isVerbose() ? new FiniteProgress("Extracting Cluster", n, LOG) : null;
for (int i = 0; i < n; i++) {
cand.reset();
multipleNodeDeletion(mat, cand);
if (LOG.isVeryVerbose()) {
LOG.veryverbose(
"Residue after Alg 2: " + cand.residue + " " + cand.rowcard + "x" + cand.colcard);
}
singleNodeDeletion(mat, cand);
if (LOG.isVeryVerbose()) {
LOG.veryverbose(
"Residue after Alg 1: " + cand.residue + " " + cand.rowcard + "x" + cand.colcard);
}
nodeAddition(mat, cand);
if (LOG.isVeryVerbose()) {
LOG.veryverbose(
"Residue after Alg 3: " + cand.residue + " " + cand.rowcard + "x" + cand.colcard);
}
cand.maskMatrix(mat, dist);
BiclusterWithInversionsModel model =
new BiclusterWithInversionsModel(colsBitsetToIDs(cand.cols), rowsBitsetToIDs(cand.irow));
final ArrayDBIDs cids = rowsBitsetToIDs(cand.rows);
noise.removeDBIDs(cids);
result.addToplevelCluster(new Cluster<>(cids, model));
if (LOG.isVerbose()) {
LOG.verbose("Score of bicluster " + (i + 1) + ": " + cand.residue + "\n");
LOG.verbose("Number of rows: " + cand.rowcard + "\n");
LOG.verbose("Number of columns: " + cand.colcard + "\n");
// LOG.verbose("Total number of masked values: " + maskedVals.size() +
// "\n");
}
LOG.incrementProcessed(prog);
}
// Add a noise cluster, full-dimensional.
if (!noise.isEmpty()) {
long[] allcols = BitsUtil.ones(getColDim());
BiclusterWithInversionsModel model =
new BiclusterWithInversionsModel(colsBitsetToIDs(allcols), DBIDUtil.EMPTYDBIDS);
result.addToplevelCluster(new Cluster<>(noise, true, model));
}
LOG.ensureCompleted(prog);
return result;
}
/**
* Handles a DataStoreEvent with the specified type. If the current event type is not equal to the
* specified type, the events accumulated up to now will be fired first.
*
* <p>The new event will be aggregated and fired on demand if {@link #accumulateDataStoreEvents}
* is set, otherwise all registered <code>DataStoreListener</code> will be notified immediately
* that the content of the database has been changed.
*
* @param object the object that has been changed, i.e. inserted, deleted or updated
*/
private void fireObjectChanged(DBIDRef object, Type type) {
// flush first
if (currentDataStoreEventType != null && !currentDataStoreEventType.equals(type)) {
flushDataStoreEvents();
}
if (this.dataStoreObjects == null) {
this.dataStoreObjects = DBIDUtil.newHashSet();
}
this.dataStoreObjects.add(object);
currentDataStoreEventType = type;
if (!accumulateDataStoreEvents) {
flushDataStoreEvents();
}
}
/**
* DBSCAN-function expandCluster.
*
* <p>Border-Objects become members of the first possible cluster.
*
* @param relation Database relation to run on
* @param rangeQuery Range query to use
* @param startObjectID potential seed of a new potential cluster
* @param objprog the progress object for logging the current status
*/
protected void expandCluster(
Relation<O> relation,
RangeQuery<O> rangeQuery,
DBIDRef startObjectID,
FiniteProgress objprog,
IndefiniteProgress clusprog) {
DoubleDBIDList neighbors = rangeQuery.getRangeForDBID(startObjectID, epsilon);
ncounter += neighbors.size();
// startObject is no core-object
if (neighbors.size() < minpts) {
noise.add(startObjectID);
processedIDs.add(startObjectID);
if (objprog != null) {
objprog.incrementProcessed(LOG);
}
return;
}
ModifiableDBIDs currentCluster = DBIDUtil.newArray();
currentCluster.add(startObjectID);
processedIDs.add(startObjectID);
// try to expand the cluster
HashSetModifiableDBIDs seeds = DBIDUtil.newHashSet();
processNeighbors(neighbors.iter(), currentCluster, seeds);
DBIDVar o = DBIDUtil.newVar();
while (!seeds.isEmpty()) {
seeds.pop(o);
neighbors = rangeQuery.getRangeForDBID(o, epsilon);
ncounter += neighbors.size();
if (neighbors.size() >= minpts) {
processNeighbors(neighbors.iter(), currentCluster, seeds);
}
if (objprog != null) {
objprog.incrementProcessed(LOG);
}
}
resultList.add(currentCluster);
if (clusprog != null) {
clusprog.setProcessed(resultList.size(), LOG);
}
}
/**
* Run the DBSCAN algorithm
*
* @param relation Data relation
* @param rangeQuery Range query class
*/
protected void runDBSCAN(Relation<O> relation, RangeQuery<O> rangeQuery) {
final int size = relation.size();
FiniteProgress objprog =
LOG.isVerbose() ? new FiniteProgress("Processing objects", size, LOG) : null;
IndefiniteProgress clusprog =
LOG.isVerbose() ? new IndefiniteProgress("Number of clusters", LOG) : null;
processedIDs = DBIDUtil.newHashSet(size);
for (DBIDIter iditer = relation.iterDBIDs(); iditer.valid(); iditer.advance()) {
if (!processedIDs.contains(iditer)) {
expandCluster(relation, rangeQuery, iditer, objprog, clusprog);
}
if (objprog != null && clusprog != null) {
objprog.setProcessed(processedIDs.size(), LOG);
clusprog.setProcessed(resultList.size(), LOG);
}
if (processedIDs.size() == size) {
break;
}
}
// Finish progress logging
LOG.ensureCompleted(objprog);
LOG.setCompleted(clusprog);
}
/**
* Evaluate a single outlier result as histogram.
*
* @param database Database to process
* @param or Outlier result
* @return Result
*/
public HistogramResult<DoubleVector> evaluateOutlierResult(Database database, OutlierResult or) {
if (scaling instanceof OutlierScalingFunction) {
OutlierScalingFunction oscaling = (OutlierScalingFunction) scaling;
oscaling.prepare(or);
}
ModifiableDBIDs ids = DBIDUtil.newHashSet(or.getScores().getDBIDs());
DBIDs outlierIds = DatabaseUtil.getObjectsByLabelMatch(database, positiveClassName);
// first value for outliers, second for each object
// If we have useful (finite) min/max, use these for binning.
double min = scaling.getMin();
double max = scaling.getMax();
final ObjHistogram<DoubleDoublePair> hist;
if (Double.isInfinite(min)
|| Double.isNaN(min)
|| Double.isInfinite(max)
|| Double.isNaN(max)) {
hist =
new AbstractObjDynamicHistogram<DoubleDoublePair>(bins) {
@Override
public DoubleDoublePair aggregate(DoubleDoublePair first, DoubleDoublePair second) {
first.first += second.first;
first.second += second.second;
return first;
}
@Override
protected DoubleDoublePair makeObject() {
return new DoubleDoublePair(0., 0.);
}
@Override
protected DoubleDoublePair cloneForCache(DoubleDoublePair data) {
return new DoubleDoublePair(data.first, data.second);
}
@Override
protected DoubleDoublePair downsample(Object[] data, int start, int end, int size) {
DoubleDoublePair sum = new DoubleDoublePair(0, 0);
for (int i = start; i < end; i++) {
DoubleDoublePair p = (DoubleDoublePair) data[i];
if (p != null) {
sum.first += p.first;
sum.second += p.second;
}
}
return sum;
}
};
} else {
hist =
new AbstractObjStaticHistogram<DoubleDoublePair>(bins, min, max) {
@Override
protected DoubleDoublePair makeObject() {
return new DoubleDoublePair(0., 0.);
}
@Override
public void putData(double coord, DoubleDoublePair data) {
DoubleDoublePair exist = get(coord);
exist.first += data.first;
exist.second += data.second;
}
};
}
// first fill histogram only with values of outliers
DoubleDoublePair negative, positive;
if (!splitfreq) {
negative = new DoubleDoublePair(1. / ids.size(), 0);
positive = new DoubleDoublePair(0, 1. / ids.size());
} else {
negative = new DoubleDoublePair(1. / (ids.size() - outlierIds.size()), 0);
positive = new DoubleDoublePair(0, 1. / outlierIds.size());
}
ids.removeDBIDs(outlierIds);
// fill histogram with values of each object
for (DBIDIter iter = ids.iter(); iter.valid(); iter.advance()) {
double result = or.getScores().doubleValue(iter);
result = scaling.getScaled(result);
if (result > Double.NEGATIVE_INFINITY && result < Double.POSITIVE_INFINITY) {
hist.putData(result, negative);
}
}
for (DBIDIter iter = outlierIds.iter(); iter.valid(); iter.advance()) {
double result = or.getScores().doubleValue(iter);
result = scaling.getScaled(result);
if (result > Double.NEGATIVE_INFINITY && result < Double.POSITIVE_INFINITY) {
hist.putData(result, positive);
}
}
Collection<DoubleVector> collHist = new ArrayList<>(hist.getNumBins());
for (ObjHistogram.Iter<DoubleDoublePair> iter = hist.iter(); iter.valid(); iter.advance()) {
DoubleDoublePair data = iter.getValue();
DoubleVector row = new DoubleVector(new double[] {iter.getCenter(), data.first, data.second});
collHist.add(row);
}
return new HistogramResult<>("Outlier Score Histogram", "outlier-histogram", collHist);
}
