/**
* 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;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.SequenceFile;
import java.io.IOException;
public final class DistributedRowMatrixWriter {
private DistributedRowMatrixWriter() {
}
public static void write(Path outputDir, Configuration conf, Iterable<MatrixSlice> matrix) throws IOException {
FileSystem fs = outputDir.getFileSystem(conf);
SequenceFile.Writer writer = SequenceFile.createWriter(fs, conf, outputDir,
IntWritable.class, VectorWritable.class);
IntWritable topic = new IntWritable();
VectorWritable vector = new VectorWritable();
for(MatrixSlice slice : matrix) {
topic.set(slice.index());
vector.set(slice.vector());
writer.append(topic, vector);
}
writer.close();
}
}