/**
* 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.meanshift;
import java.io.IOException;
import java.util.regex.Pattern;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.io.WritableComparable;
import org.apache.hadoop.mapreduce.Mapper;
import org.apache.mahout.clustering.iterator.ClusterWritable;
import org.apache.mahout.clustering.kmeans.KMeansConfigKeys;
import org.apache.mahout.common.ClassUtils;
import org.apache.mahout.common.distance.DistanceMeasure;
import org.apache.mahout.math.VectorWritable;
import com.google.common.base.Preconditions;
@Deprecated
public class MeanShiftCanopyCreatorMapper extends Mapper<WritableComparable<?>, VectorWritable, Text, ClusterWritable> {
private static final Pattern UNDERSCORE_PATTERN = Pattern.compile("_");
private static int nextCanopyId = -1;
private DistanceMeasure measure;
@Override
protected void map(WritableComparable<?> key, VectorWritable point, Context context)
throws IOException, InterruptedException {
MeanShiftCanopy canopy = MeanShiftCanopy.initialCanopy(point.get(), nextCanopyId++, measure);
ClusterWritable clusterWritable = new ClusterWritable();
clusterWritable.setValue(canopy);
context.write(new Text(key.toString()), clusterWritable);
}
@Override
protected void setup(Context context) throws IOException, InterruptedException {
super.setup(context);
String measureClass = context.getConfiguration().get(KMeansConfigKeys.DISTANCE_MEASURE_KEY);
measure = ClassUtils.instantiateAs(measureClass, DistanceMeasure.class);
if (nextCanopyId == -1) {
String taskId = context.getConfiguration().get("mapred.task.id");
String[] parts = UNDERSCORE_PATTERN.split(taskId);
Preconditions.checkArgument(parts.length == 6
&& "attempt".equals(parts[0])
&& ("m".equals(parts[3]) || "r".equals(parts[3])),
"TaskAttemptId string: %d is not properly formed", taskId);
nextCanopyId = ((1 << 31) / 50000) * Integer.parseInt(parts[4]);
//each mapper has 42,949 ids to give.
}
}
}