org.apache.mahout.math.hadoop.TransposeJob.java Source code

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Here is the source code for org.apache.mahout.math.hadoop.TransposeJob.java

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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.math.hadoop;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.lib.input.SequenceFileInputFormat;
import org.apache.hadoop.mapreduce.lib.output.SequenceFileOutputFormat;
import org.apache.hadoop.util.ToolRunner;
import org.apache.mahout.common.AbstractJob;
import org.apache.mahout.common.HadoopUtil;
import org.apache.mahout.common.mapreduce.MergeVectorsCombiner;
import org.apache.mahout.common.mapreduce.MergeVectorsReducer;
import org.apache.mahout.common.mapreduce.TransposeMapper;
import org.apache.mahout.math.VectorWritable;

import java.io.IOException;
import java.util.List;
import java.util.Map;

/** Transpose a matrix */
public class TransposeJob extends AbstractJob {

    public static void main(String[] args) throws Exception {
        ToolRunner.run(new TransposeJob(), args);
    }

    @Override
    public int run(String[] strings) throws Exception {
        addInputOption();
        addOption("numRows", "nr", "Number of rows of the input matrix");
        addOption("numCols", "nc", "Number of columns of the input matrix");
        Map<String, List<String>> parsedArgs = parseArguments(strings);
        if (parsedArgs == null) {
            return -1;
        }

        int numRows = Integer.parseInt(getOption("numRows"));
        int numCols = Integer.parseInt(getOption("numCols"));

        DistributedRowMatrix matrix = new DistributedRowMatrix(getInputPath(), getTempPath(), numRows, numCols);
        matrix.setConf(new Configuration(getConf()));
        matrix.transpose();

        return 0;
    }

    public static Job buildTransposeJob(Path matrixInputPath, Path matrixOutputPath, int numInputRows)
            throws IOException {
        return buildTransposeJob(new Configuration(), matrixInputPath, matrixOutputPath, numInputRows);
    }

    public static Job buildTransposeJob(Configuration initialConf, Path matrixInputPath, Path matrixOutputPath,
            int numInputRows) throws IOException {

        Job job = HadoopUtil.prepareJob(matrixInputPath, matrixOutputPath, SequenceFileInputFormat.class,
                TransposeMapper.class, IntWritable.class, VectorWritable.class, MergeVectorsReducer.class,
                IntWritable.class, VectorWritable.class, SequenceFileOutputFormat.class, initialConf);
        job.setCombinerClass(MergeVectorsCombiner.class);
        job.getConfiguration().setInt(TransposeMapper.NEW_NUM_COLS_PARAM, numInputRows);

        job.setJobName("TransposeJob: " + matrixInputPath);

        return job;
    }

}