/**
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.mahout.clustering.canopy;
import java.io.IOException;
import java.util.Collection;
import com.google.common.collect.Lists;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Reducer;
import org.apache.mahout.clustering.iterator.ClusterWritable;
import org.apache.mahout.math.Vector;
import org.apache.mahout.math.VectorWritable;
public class CanopyReducer extends Reducer<Text, VectorWritable, Text, ClusterWritable> {
private final Collection<Canopy> canopies = Lists.newArrayList();
private CanopyClusterer canopyClusterer;
private int clusterFilter;
CanopyClusterer getCanopyClusterer() {
return canopyClusterer;
}
@Override
protected void reduce(Text arg0, Iterable<VectorWritable> values,
Context context) throws IOException, InterruptedException {
for (VectorWritable value : values) {
Vector point = value.get();
canopyClusterer.addPointToCanopies(point, canopies);
}
for (Canopy canopy : canopies) {
canopy.computeParameters();
if (canopy.getNumObservations() > clusterFilter) {
ClusterWritable clusterWritable = new ClusterWritable();
clusterWritable.setValue(canopy);
context.write(new Text(canopy.getIdentifier()), clusterWritable);
}
}
}
@Override
protected void setup(Context context) throws IOException,
InterruptedException {
super.setup(context);
canopyClusterer = new CanopyClusterer(context.getConfiguration());
canopyClusterer.useT3T4();
clusterFilter = Integer.parseInt(context.getConfiguration().get(
CanopyConfigKeys.CF_KEY));
}
}