/**
* 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 java.util.ArrayList;
import java.util.List;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.io.WritableComparable;
import org.apache.hadoop.mapred.JobConf;
import org.apache.hadoop.mapred.MapReduceBase;
import org.apache.hadoop.mapred.Mapper;
import org.apache.hadoop.mapred.OutputCollector;
import org.apache.hadoop.mapred.Reporter;
import org.apache.mahout.matrix.AbstractVector;
import org.apache.mahout.matrix.Vector;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
public class FuzzyKMeansMapper extends MapReduceBase implements
Mapper<WritableComparable<?>, Text, Text, Text> {
private static final Logger log = LoggerFactory.getLogger(FuzzyKMeansMapper.class);
protected List<SoftCluster> clusters;
@Override
public void map(WritableComparable<?> key, Text values,
OutputCollector<Text, Text> output, Reporter reporter) throws IOException {
Vector point = AbstractVector.decodeVector(values.toString());
SoftCluster.emitPointProbToCluster(point, clusters, values, output);
}
/**
* Configure the mapper by providing its clusters. Used by unit tests.
*
* @param clusters a List<Cluster>
*/
void config(List<SoftCluster> clusters) {
this.clusters = clusters;
}
@Override
public void configure(JobConf job) {
super.configure(job);
SoftCluster.configure(job);
log.info("In Mapper Configure:");
clusters = new ArrayList<SoftCluster>();
FuzzyKMeansUtil.configureWithClusterInfo(job
.get(SoftCluster.CLUSTER_PATH_KEY), clusters);
if (clusters.isEmpty())
throw new NullPointerException("Cluster is empty!!!");
}
}