/**
* 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.test;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Mapper;
import org.apache.mahout.classifier.naivebayes.AbstractNaiveBayesClassifier;
import org.apache.mahout.classifier.naivebayes.ComplementaryNaiveBayesClassifier;
import org.apache.mahout.classifier.naivebayes.NaiveBayesModel;
import org.apache.mahout.classifier.naivebayes.StandardNaiveBayesClassifier;
import org.apache.mahout.common.HadoopUtil;
import org.apache.mahout.math.Vector;
import org.apache.mahout.math.VectorWritable;
import java.io.IOException;
import java.util.regex.Pattern;
/**
* Run the input through the model and see if it matches.
* <p/>
* The output value is the generated label, the Pair is the expected label and true if they match:
*/
public class BayesTestMapper extends Mapper<Text, VectorWritable, Text, VectorWritable> {
private static final Pattern SLASH = Pattern.compile("/");
private AbstractNaiveBayesClassifier classifier;
@Override
protected void setup(Context context) throws IOException, InterruptedException {
super.setup(context);
Configuration conf = context.getConfiguration();
Path modelPath = HadoopUtil.getSingleCachedFile(conf);
NaiveBayesModel model = NaiveBayesModel.materialize(modelPath, conf);
boolean compl = Boolean.parseBoolean(conf.get(TestNaiveBayesDriver.COMPLEMENTARY));
if (compl) {
classifier = new ComplementaryNaiveBayesClassifier(model);
} else {
classifier = new StandardNaiveBayesClassifier(model);
}
}
@Override
protected void map(Text key, VectorWritable value, Context context) throws IOException, InterruptedException {
Vector result = classifier.classifyFull(value.get());
//the key is the expected value
context.write(new Text(SLASH.split(key.toString())[1]), new VectorWritable(result));
}
}