/**
* 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.rbm.training;
import java.util.Iterator;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.mapreduce.Reducer;
import org.apache.mahout.math.Matrix;
import org.apache.mahout.math.MatrixWritable;
/**
* The Class DBMBackPropTrainingReducer.
*/
public class DBMBackPropTrainingReducer extends Reducer<IntWritable,MatrixWritable,IntWritable,MatrixWritable>{
/* (non-Javadoc)
* @see org.apache.hadoop.mapreduce.Reducer#reduce(KEYIN, java.lang.Iterable, org.apache.hadoop.mapreduce.Reducer.Context)
*/
protected void reduce(IntWritable key, Iterable<MatrixWritable> matrices, Context context) throws java.io.IOException ,InterruptedException {
if(!matrices.iterator().hasNext())
return;
Matrix result = matrices.iterator().next().get();
for (Iterator<MatrixWritable> iterator = matrices.iterator(); iterator.hasNext();) {
result = result.plus(iterator.next().get());
}
context.write(key, new MatrixWritable(result));
};
}