/*
* Source code for Listing 6.3
*
*/
package mia.recommender.ch06;
import java.io.IOException;
import java.util.Iterator;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.mapreduce.Mapper;
import org.apache.mahout.math.VarLongWritable;
import org.apache.mahout.math.VectorWritable;
import org.apache.mahout.math.Vector;
public class UserVectorToCooccurrenceMapper extends
Mapper<VarLongWritable, VectorWritable, IntWritable, IntWritable> {
public void map(VarLongWritable userID, VectorWritable userVector,
Context context) throws IOException, InterruptedException {
Iterator<Vector.Element> it = userVector.get().iterateNonZero();
while (it.hasNext()) {
int index1 = it.next().index();
Iterator<Vector.Element> it2 = userVector.get().iterateNonZero();
while (it2.hasNext()) {
int index2 = it2.next().index();
context.write(new IntWritable(index1), new IntWritable(index2));
}
}
}
}