/*
* 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.conversion.meanshift;
import java.io.IOException;
import java.util.Collection;
import java.util.regex.Pattern;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Mapper;
import org.apache.mahout.clustering.iterator.ClusterWritable;
import org.apache.mahout.clustering.meanshift.MeanShiftCanopy;
import org.apache.mahout.common.distance.EuclideanDistanceMeasure;
import org.apache.mahout.math.DenseVector;
import org.apache.mahout.math.Vector;
import com.google.common.collect.Lists;
public class InputMapper extends Mapper<LongWritable,Text,Text,ClusterWritable> {
private static final Pattern SPACE = Pattern.compile(" ");
private int nextCanopyId;
private final ClusterWritable cw = new ClusterWritable();
@Override
protected void map(LongWritable key, Text values, Context context) throws IOException, InterruptedException {
String[] numbers = SPACE.split(values.toString());
// sometimes there are multiple separator spaces
Collection<Double> doubles = Lists.newArrayList();
for (String value : numbers) {
if (!value.isEmpty()) {
doubles.add(Double.valueOf(value));
}
}
// ignore empty lines in input data
if (!doubles.isEmpty()) {
Vector point = new DenseVector(doubles.size());
int index = 0;
for (Double d : doubles) {
point.set(index++, d);
}
cw.setValue(new MeanShiftCanopy(point, nextCanopyId++, new EuclideanDistanceMeasure()));
context.write(new Text(), cw);
}
}
}