/**
* Calculate the average similarity to the cluster
*
* @param document the target document
* @param cluster the target cluster
* @param datasetHandler dataset handler
* @param neo4jHandler neo4j handler
* @return the average similarity
* @throws IOException
* @throws ClassNotFoundException
*/
private double calculateAvgSimilairtyToCluster(
Neo4jDocument document,
Neo4jCluster cluster,
DatasetLoader datasetHandler,
Neo4jHandler neo4jHandler)
throws IOException, ClassNotFoundException {
double similairty = 0;
DDSimIF similairtyCalculator = new DDSimilairty();
ArrayList<Neo4jDocument> clusterDocuments =
cluster.getDocumentsList(datasetHandler, neo4jHandler);
for (Iterator iterator = clusterDocuments.iterator(); iterator.hasNext(); ) {
Neo4jDocument neo4jDocument = (Neo4jDocument) iterator.next();
similairty +=
similairtyCalculator.calculateSimilarity(
document, neo4jDocument, datasetHandler.numberOfDocuments());
}
return similairty / clusterDocuments.size();
}
public Hashtable<String, Neo4jCluster> perform(
DatasetLoader datasetHandler,
Neo4jHandler neo4jHandler,
double similairtyThreshold,
int softClusteringThreshold)
throws Exception {
Hashtable<String, Neo4jCluster> clustersList = new Hashtable<String, Neo4jCluster>();
Hashtable<String, Document> docsHash = datasetHandler.loadDocuments();
DDSimIF similarityCalculator = new DDSimilairty();
Enumeration e = docsHash.keys();
int numberOfClusters = 0;
// loop for documents in the dataset
while (e.hasMoreElements()) {
Hashtable<String, Double> candidateClustersHash = new Hashtable<String, Double>();
String documentID = (String) e.nextElement();
System.out.println("Processing document " + documentID);
Document document = docsHash.get(documentID);
Neo4jDocument neo4jDocument = neo4jHandler.loadDocument(document);
boolean clusteredYet = false;
// get similar documents to the document
ArrayList<Neo4jDocument> similarDocuments =
getSimilarDocuments(neo4jDocument, neo4jHandler, datasetHandler);
// loop over the similar documents
for (Iterator iterator = similarDocuments.iterator(); iterator.hasNext(); ) {
Neo4jDocument neo4jSimilarDocument = (Neo4jDocument) iterator.next();
// continue if the current similar document has no clusters
if (neo4jSimilarDocument.getClustersHash().isEmpty()) continue;
// check if the distance to the document is greater than the threshold
if (similarityCalculator.calculateSimilarity(
neo4jDocument, neo4jSimilarDocument, datasetHandler.numberOfDocuments())
> similairtyThreshold) {
// get the clusters of the similar document
ArrayList<String> candidateDocumentClustersIDs = neo4jSimilarDocument.getClusterIDsList();
// loop over the clusters of the similar document
for (Iterator iterator2 = candidateDocumentClustersIDs.iterator();
iterator2.hasNext(); ) { // loop for candidate clusters
String candidateClusterID = (String) iterator2.next();
// get the cluster
Neo4jCluster candidateNeo4jCluster = clustersList.get(candidateClusterID);
// calculate the average similarity to the cluster
double averageSimilairtyToCluster =
calculateAvgSimilairtyToCluster(
neo4jDocument, candidateNeo4jCluster, datasetHandler, neo4jHandler);
// if the average similarity greater the the threshold then the cluster to the candidate
// clusters
if (averageSimilairtyToCluster > similairtyThreshold) {
clusteredYet = true;
candidateClustersHash.put(candidateClusterID, averageSimilairtyToCluster);
} // end if adding cluster to candidate cluster hash
} // end loop for candidate clusters
} // end if [checking if the distance to the candidate document is less than the threshold]
} // end looping for similar documents
if (!clusteredYet) { // create new cluster
numberOfClusters++;
Neo4jCluster newCluster = new Neo4jCluster(String.valueOf(numberOfClusters));
newCluster.addDcoument(documentID);
neo4jDocument.addCluster(newCluster.getId(), 1);
clustersList.put(newCluster.getId(), newCluster);
} else { // add to the cloeset cluster
String nearestClusterID = getNearestCluster(candidateClustersHash);
Neo4jCluster cluster = clustersList.get(nearestClusterID);
cluster.addDcoument(neo4jDocument.getDocumentID());
neo4jDocument.addCluster(nearestClusterID, 1);
}
} // end loop for all documents in the data set
return clustersList;
}
