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@dfilimon
Created November 8, 2012 13:13
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This compiles file, but I'm having classpath issues.
package org.apache.mahout.knn.experimental;
import com.google.common.collect.Lists;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.SequenceFile;
import org.apache.hadoop.io.Text;
import org.apache.mahout.clustering.Cluster;
import org.apache.mahout.clustering.classify.WeightedVectorWritable;
import org.apache.mahout.clustering.kmeans.KMeansDriver;
import org.apache.mahout.clustering.kmeans.Kluster;
import org.apache.mahout.common.distance.EuclideanDistanceMeasure;
import org.apache.mahout.math.RandomAccessSparseVector;
import org.apache.mahout.math.Vector;
import org.apache.mahout.math.VectorWritable;
import org.apache.mahout.math.WeightedVector;
import java.io.File;
import java.io.IOException;
import java.util.List;
public class BasicKMeans {
public static final double[][] points = {
{1, 1}, {2, 1}, {1, 2},
{2, 2}, {3, 3}, {8, 8},
{9, 8}, {8, 9}, {9, 9}
};
/**
* Writes a list of Vectors to a sequence file as pairs of (LongWritable,
* VectorWritable) where LongWritable is the key (the record index in this case) and
* VectorWritable is the value.
*
* @param points the list of vectors to be written.
* @param fileName the path of the sequence file to be created.
* @param fs the HDFS FileSystem object to write this file on.
* @param conf the Hadoop configuration file to write this file on.
* @throws IOException
*/
public static void writePointsToFile(List<Vector> points, String fileName, FileSystem fs,
Configuration conf) throws IOException {
Path path = new Path(fileName);
SequenceFile.Writer writer = new SequenceFile.Writer(fs, conf, path,
LongWritable.class, VectorWritable.class);
long recNum = 0;
VectorWritable vec = new VectorWritable();
for (Vector point : points) {
vec.set(point);
writer.append(new LongWritable(recNum++), vec);
}
writer.close();
}
/**
* Creates a List<Vector> from a 2D array of raw vectors.
*
* @param raw the array of vectors to be converted.
* @return
*/
public static List<Vector> getPoints(double[][] raw) {
List<Vector> points = Lists.newArrayList();
for (int i = 0; i < raw.length; ++i) {
double[] fr = raw[i];
Vector vec = new RandomAccessSparseVector(fr.length);
vec.assign(fr);
points.add(vec);
}
return points;
}
public static void main(String args[]) throws Exception {
// The number of clusters to be formed.
int numClusters = 2;
List<Vector> vectors = getPoints(points);
File testData = new File("testdata");
if (!testData.exists()) {
testData.mkdir();
}
testData = new File("testdata/points");
if (!testData.exists()) {
testData.mkdir();
}
Configuration conf = new Configuration();
FileSystem fs = FileSystem.get(conf);
// Wrote the generated vectors to a sequence file.
writePointsToFile(vectors, "testdata/points/file1", fs, conf);
Path path = new Path("testdata/clusters/part-00000");
SequenceFile.Writer writer = new SequenceFile.Writer(fs, conf, path, Text.class,
Cluster.class);
// Prepare the initial set of centroids.
for (int i = 0; i < numClusters; ++i) {
Vector vec = vectors.get(i);
Cluster cluster = new Kluster(vec, i, new EuclideanDistanceMeasure());
writer.append(new Text(cluster.asFormatString(null)), cluster);
}
writer.close();
// Run the KMeans algorithm.
KMeansDriver.run(conf,
new Path("testdata/points/"), new Path("testdata/clusters"), new Path("output/"),
new EuclideanDistanceMeasure(),
0.0001, // convergenceDelta
10, // maxIterations
true, // runClustering
0.01, // clusterClassificationThreshold
false // runSequential (if false, runs as MapReduce
);
// Print out final results.
SequenceFile.Reader reader = new SequenceFile.Reader(fs,
new Path("output/" + Cluster.CLUSTERED_POINTS_DIR + "/part-m-00000"), conf);
IntWritable key = new IntWritable();
WeightedVectorWritable value = new WeightedVectorWritable();
while (reader.next(key, value)) {
System.out.println(value.toString() + " belongs to cluster " + key.toString());
}
reader.close();
}
}
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