@Override
public Tuple2<String, Instance> call(Tuple2<String, Instance> inst) throws Exception {
Instance bestCluster = null;
double bestScore = Double.MAX_VALUE;
for (String clusterId : clusters.keySet()) {
Instance cluster = clusters.get(clusterId);
double d = distFunc.distance(inst._2, cluster);
if (d < bestScore && d < threshold) {
bestScore = d;
bestCluster = cluster;
}
}
// System.out.println(inst._1 + " -> " + bestCluster);
if (bestCluster == null) {
return null;
}
return new Tuple2<String, Instance>(bestCluster.getId(), inst._2);
}
@Override
public ClusterContext clusterEntities(
Collection<FL_Entity> entities,
Collection<FL_Cluster> immutableClusters,
Collection<FL_Cluster> clusters,
ClusterContext context) {
Map<String, FL_Entity> entityIndex = createEntityIndex(entities);
Map<String, FL_Cluster> immutableClusterIndex = createClusterIndex(immutableClusters);
Map<String, FL_Cluster> clusterIndex = createClusterIndex(clusters);
DataSet ds = createDataSet(entities, immutableClusters, context);
BaseClusterer clusterer = createNumericClusterer();
List<Cluster> existingClusters = new LinkedList<Cluster>();
for (FL_Cluster cluster : clusters) {
double val = 0;
PropertyHelper prop = getFirstProperty(cluster, toClusterPropertyName(clusterField));
if (prop != null) {
val = getDoubleValue(prop);
}
Cluster c = clusterer.createCluster();
c.setId(cluster.getUid());
NumericVectorFeature feature = new NumericVectorFeature("num");
feature.setValue(new double[] {val});
c.addFeature(feature);
existingClusters.add(c);
}
ClusterResult rs = null;
if (existingClusters.isEmpty()) {
rs = clusterer.doCluster(ds);
} else {
rs = clusterer.doIncrementalCluster(ds, existingClusters);
}
// clean up
clusterer.terminate();
Map<String, FL_Cluster> modifiedClusters = new HashMap<String, FL_Cluster>();
for (Cluster c : rs) {
List<FL_Cluster> subClusters = new LinkedList<FL_Cluster>();
List<FL_Entity> members = new LinkedList<FL_Entity>();
for (Instance inst : c.getMembers()) {
String id = inst.getId();
if (entityIndex.containsKey(id)) {
members.add(entityIndex.get(id));
} else if (immutableClusterIndex.containsKey(id)) {
subClusters.add(immutableClusterIndex.get(id));
}
}
FL_Cluster cluster = clusterIndex.get(c.getId());
if (cluster == null) {
cluster = clusterFactory.toCluster(members, subClusters);
// cache the cluster property
NumericVectorFeature feature = (NumericVectorFeature) c.getFeature("num");
double value = feature.getValue()[0];
addClusterProperty(cluster, clusterField, value);
} else {
ClusterHelper.addMembers(cluster, members);
EntityClusterFactory.setEntityCluster(members, cluster);
for (FL_Cluster subCluster : subClusters) {
ClusterHelper.addSubCluster(cluster, subCluster);
subCluster.setParent(cluster.getUid());
}
// cache the cluster property
NumericVectorFeature feature = (NumericVectorFeature) c.getFeature("num");
double value = feature.getValue()[0];
addClusterProperty(cluster, clusterField, value);
}
modifiedClusters.put(cluster.getUid(), cluster);
}
ClusterContext result = new ClusterContext();
result.roots.putAll(modifiedClusters);
result.clusters.putAll(modifiedClusters);
return result;
}