Mahout clustered points - cluster-analysis

Question

When I run kmeans clustering in Mahoot I get two folders, clusters-x and clusteredPoints.
I have read cluster centers using cluster dumper, but I somehow can't get to clusteredPoints? Concretely, I need to do it from code.
The strange thing is that I file size in clusteredPoints is always 128 bytes, and when I try to loop through results, using next code, it just goes out of the loop, like there is no result, but I get the cluster centers, which leads to assumption that points are clustered.
IntWritable key = new IntWritable();
WeightedPropertyVectorWritable value = new WeightedPropertyVectorWritable();
while (reader.next(key, value)) {
System.out.println(
value.toString() + " belongs to cluster " + key.toString());
}
It just goes out of the loop?
It is really strange, any help would be great, thanks.

Answer 1

You need to open up your final cluster file ('clusteredPoints/part-m-0') with:
Configuration conf = new Configuration();
FileSystem fs = FileSystem.get(conf);
SequenceFile.Reader reader = new SequenceFile.Reader(fs, new Path("output/clusteredPoints/part-m-0"), conf);
then, assuming your keys are int's, iterate through it (as you already did), with:
IntWritable key = new IntWritable();
WeightedPropertyVectorWritable value = new WeightedPropertyVectorWritable();
while (reader.next(key, value)) {
LOG.info("{} belongs to cluster {}", value.toString(), key.toString());
}
reader.close();
I can post a fully working example if you still have trouble doing this.