public IList<ClusterResult> Cluster(int k)
{
using (FileStream indexFileStream = File.Open(indexFilePath, FileMode.Open))
{
using (FileStream metadataFileStream = File.Open(metadataFilePath, FileMode.Open))
{
IndexMetadata indexMetadata = new IndexMetadata(metadataFileStream);
TermIndex index = new TermIndex(indexFileStream);
QueryEngine queryEngine = new QueryEngine(index, indexMetadata);
KMeansClusterFinder clusterFinder = new KMeansClusterFinder(indexMetadata, index);
IList<long> allDocIds = indexMetadata.GetDocumentIds();
long[][] clusters = clusterFinder.Cluster(allDocIds, k);
IList<ClusterResult> clusterResults = new List<ClusterResult>();
foreach (long[] cluster in clusters)
{
// Get the term frequencies in the collection
IEnumerable<DocumentInfo> clusterDocuments = indexMetadata.GetDocuments(cluster);
TermVector sum = new TermVector();
foreach (TermVector vector in clusterDocuments.Select(d => d.TermVector))
{
sum += vector;
}
IEnumerable<string> topTerms =
TermVector.GetCentroid(indexMetadata.GetDocuments(cluster)
.Select(docInfo => docInfo.TermVector))
.GetNonZeroDimensions()
.OrderByDescending(term => sum.GetDimensionLength(term) * this.GetIdf(index, indexMetadata, term))
.Take(6);
clusterResults.Add(new ClusterResult(topTerms.ToList(),
clusterDocuments.Select(docInfo => docInfo.Uri).ToList()));
}
return clusterResults;
}
}
}
private void Cluster(string args)
{
int k = int.Parse(args);
Console.WriteLine("Clustering...");
KMeansClusterFinder clusterFinder = new KMeansClusterFinder(this.metadata, this.index);
IList<long> allDocIds = this.metadata.GetDocumentIds();
long[][] clusters = clusterFinder.Cluster(allDocIds, k);
int i = 1;
Console.WriteLine("Done! Here are top terms for each cluster:");
foreach(long[] cluster in clusters)
{
IEnumerable<DocumentInfo> clusterDocuments = this.metadata.GetDocuments(cluster);
TermVector sum = new TermVector();
foreach (TermVector vector in clusterDocuments.Select(d => d.TermVector))
{
sum += vector;
}
IEnumerable<string> topTerms =
TermVector.GetCentroid(this.metadata.GetDocuments(cluster)
.Select(docInfo => docInfo.TermVector))
.GetNonZeroDimensions()
.OrderByDescending(term => sum.GetDimensionLength(term)*this.GetIdf(term))
.Take(6);
Console.Write(i + ": ");
if (topTerms.Count() == 0)
{
Console.Write("Empty cluster!");
Console.WriteLine();
}
else
{
foreach (string term in topTerms)
{
Console.Write(term+" ");
}
Console.WriteLine();
}
i++;
}
}