/**
* 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.math.hadoop;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.mapred.FileOutputFormat;
import org.apache.hadoop.mapred.JobConf;
import org.apache.hadoop.mapred.MapReduceBase;
import org.apache.hadoop.mapred.Mapper;
import org.apache.hadoop.mapred.OutputCollector;
import org.apache.hadoop.mapred.Reducer;
import org.apache.hadoop.mapred.Reporter;
import org.apache.hadoop.mapred.SequenceFileInputFormat;
import org.apache.hadoop.mapred.SequenceFileOutputFormat;
import org.apache.hadoop.mapred.join.CompositeInputFormat;
import org.apache.hadoop.mapred.join.TupleWritable;
import org.apache.hadoop.util.ToolRunner;
import org.apache.mahout.common.AbstractJob;
import org.apache.mahout.math.RandomAccessSparseVector;
import org.apache.mahout.math.SequentialAccessSparseVector;
import org.apache.mahout.math.Vector;
import org.apache.mahout.math.VectorWritable;
import org.apache.mahout.math.function.Functions;
import java.io.IOException;
import java.util.Iterator;
import java.util.Map;
public class MatrixMultiplicationJob extends AbstractJob {
private static final String OUT_CARD = "output.vector.cardinality";
public static Configuration createMatrixMultiplyJobConf(Path aPath,
Path bPath,
Path outPath,
int outCardinality) {
return createMatrixMultiplyJobConf(new Configuration(), aPath, bPath, outPath, outCardinality);
}
public static Configuration createMatrixMultiplyJobConf(Configuration initialConf,
Path aPath,
Path bPath,
Path outPath,
int outCardinality) {
JobConf conf = new JobConf(initialConf, MatrixMultiplicationJob.class);
conf.setInputFormat(CompositeInputFormat.class);
conf.set("mapred.join.expr", CompositeInputFormat.compose(
"inner", SequenceFileInputFormat.class, aPath, bPath));
conf.setInt(OUT_CARD, outCardinality);
conf.setOutputFormat(SequenceFileOutputFormat.class);
FileOutputFormat.setOutputPath(conf, outPath);
conf.setMapperClass(MatrixMultiplyMapper.class);
conf.setCombinerClass(MatrixMultiplicationReducer.class);
conf.setReducerClass(MatrixMultiplicationReducer.class);
conf.setMapOutputKeyClass(IntWritable.class);
conf.setMapOutputValueClass(VectorWritable.class);
conf.setOutputKeyClass(IntWritable.class);
conf.setOutputValueClass(VectorWritable.class);
return conf;
}
public static void main(String[] args) throws Exception {
ToolRunner.run(new MatrixMultiplicationJob(), args);
}
@Override
public int run(String[] strings) throws Exception {
addOption("numRowsA", "nra", "Number of rows of the first input matrix", true);
addOption("numColsA", "nca", "Number of columns of the first input matrix", true);
addOption("numRowsB", "nrb", "Number of rows of the second input matrix", true);
addOption("numColsB", "ncb", "Number of columns of the second input matrix", true);
addOption("inputPathA", "ia", "Path to the first input matrix", true);
addOption("inputPathB", "ib", "Path to the second input matrix", true);
Map<String, String> argMap = parseArguments(strings);
if (argMap == null) {
return -1;
}
DistributedRowMatrix a = new DistributedRowMatrix(new Path(argMap.get("--inputPathA")),
new Path(argMap.get("--tempDir")),
Integer.parseInt(argMap.get("--numRowsA")),
Integer.parseInt(argMap.get("--numColsA")));
DistributedRowMatrix b = new DistributedRowMatrix(new Path(argMap.get("--inputPathB")),
new Path(argMap.get("--tempDir")),
Integer.parseInt(argMap.get("--numRowsB")),
Integer.parseInt(argMap.get("--numColsB")));
a.setConf(new Configuration(getConf()));
b.setConf(new Configuration(getConf()));
//DistributedRowMatrix c = a.times(b);
a.times(b);
return 0;
}
public static class MatrixMultiplyMapper extends MapReduceBase
implements Mapper<IntWritable,TupleWritable,IntWritable,VectorWritable> {
private int outCardinality;
private final IntWritable row = new IntWritable();
@Override
public void configure(JobConf conf) {
outCardinality = conf.getInt(OUT_CARD, Integer.MAX_VALUE);
}
@Override
public void map(IntWritable index,
TupleWritable v,
OutputCollector<IntWritable,VectorWritable> out,
Reporter reporter) throws IOException {
boolean firstIsOutFrag = ((VectorWritable)v.get(0)).get().size() == outCardinality;
Vector outFrag = firstIsOutFrag ? ((VectorWritable)v.get(0)).get() : ((VectorWritable)v.get(1)).get();
Vector multiplier = firstIsOutFrag ? ((VectorWritable)v.get(1)).get() : ((VectorWritable)v.get(0)).get();
VectorWritable outVector = new VectorWritable();
Iterator<Vector.Element> it = multiplier.iterateNonZero();
while (it.hasNext()) {
Vector.Element e = it.next();
row.set(e.index());
outVector.set(outFrag.times(e.get()));
out.collect(row, outVector);
}
}
}
public static class MatrixMultiplicationReducer extends MapReduceBase
implements Reducer<IntWritable,VectorWritable,IntWritable,VectorWritable> {
@Override
public void reduce(IntWritable rowNum,
Iterator<VectorWritable> it,
OutputCollector<IntWritable,VectorWritable> out,
Reporter reporter) throws IOException {
if (!it.hasNext()) {
return;
}
Vector accumulator = new RandomAccessSparseVector(it.next().get());
while (it.hasNext()) {
Vector row = it.next().get();
accumulator.assign(row, Functions.PLUS);
}
out.collect(rowNum, new VectorWritable(new SequentialAccessSparseVector(accumulator)));
}
}
}