/**
* 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.fuzzykmeans;
import java.io.IOException;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Reducer;
import org.apache.mahout.clustering.ClusterObservations;
public class FuzzyKMeansCombiner extends Reducer<Text, ClusterObservations, Text, ClusterObservations> {
private FuzzyKMeansClusterer clusterer;
@Override
protected void reduce(Text key, Iterable<ClusterObservations> values, Context context)
throws IOException, InterruptedException {
SoftCluster cluster = new SoftCluster();
for (ClusterObservations value : values) {
if (value.getCombinerState() == 0) { // first time through combiner
cluster.observe(value.getS1(), Math.pow(value.getS0(), clusterer.getM()));
} else {
cluster.observe(value);
}
}
context.write(key, cluster.getObservations().incrementCombinerState());
}
@Override
protected void setup(Context context) throws IOException, InterruptedException {
super.setup(context);
clusterer = new FuzzyKMeansClusterer(context.getConfiguration());
}
}