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/**
* 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.classifier.naivebayes.training;
import java.io.IOException;
import java.util.regex.Pattern;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Mapper;
import org.apache.mahout.classifier.naivebayes.BayesUtils;
import org.apache.mahout.math.VectorWritable;
import org.apache.mahout.math.map.OpenObjectIntHashMap;
public class IndexInstancesMapper extends Mapper {
private static final Pattern SLASH = Pattern.compile("/");
public enum Counter { SKIPPED_INSTANCES }
private OpenObjectIntHashMap labelIndex;
@Override
protected void setup(Context ctx) throws IOException, InterruptedException {
super.setup(ctx);
labelIndex = BayesUtils.readIndexFromCache(ctx.getConfiguration());
}
@Override
protected void map(Text labelText, VectorWritable instance, Context ctx) throws IOException, InterruptedException {
String label = SLASH.split(labelText.toString())[1];
if (labelIndex.containsKey(label)) {
ctx.write(new IntWritable(labelIndex.get(label)), instance);
} else {
ctx.getCounter(Counter.SKIPPED_INSTANCES).increment(1);
}
}
}
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