root.input.util.CreateSeedVector.java Source code

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Here is the source code for root.input.util.CreateSeedVector.java

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/**
 * Copyright 2013 AMALTHEA REU; Dillon Rose; Michel Rouly
 * 
 * Licensed 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 root.input.util;

import java.io.IOException;
import java.net.URI;
import java.net.URISyntaxException;
import java.util.Collections;
import java.util.List;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.SequenceFile;
import org.apache.hadoop.io.Text;
import org.apache.mahout.math.NamedVector;
import org.apache.mahout.math.Vector;
import org.apache.mahout.math.VectorWritable;

import com.google.common.collect.Lists;

/**
 * <p>
 * Create list of seed vectors for use in construction of similarity matrix.
 * </p>
 * 
 * @author Dillon Rose
 * @author Michel Rouly
 * 
 * @since 2013.06.25
 * 
 * @see CreateSimilarityMatrixJob
 * @see SimilarityMatrixMapper
 * 
 */
final class CreateSeedVector {

    /**
     * Load in the seed vectors which will be used for the similarity matrix.
     * 
     * @param conf configuration file
     * @return list of configured seed vectors
     */
    public static List<NamedVector> loadSeedVectors(Configuration conf) throws IOException, URISyntaxException {

        String seedPathStr = conf.get(CreateSimilarityMatrixJob.SEEDS_PATH_KEY);
        if (seedPathStr == null || seedPathStr.isEmpty()) {
            return Collections.emptyList();
        }

        List<NamedVector> seedVectors = Lists.newArrayList();

        Path seedsDirPath = new Path(seedPathStr + "/part-r-00000");

        URI uri = new URI(conf.get("fs.default.name"));
        FileSystem fs = FileSystem.get(uri, conf);

        SequenceFile.Reader reader = new SequenceFile.Reader(fs, seedsDirPath, conf);

        Text key = new Text();
        VectorWritable value = new VectorWritable();

        while (reader.next(key, value)) {
            VectorWritable vw = (VectorWritable) value;
            Vector vector = vw.get();
            seedVectors.add(new NamedVector(vector, key.toString()));
        }

        reader.close();

        if (seedVectors.isEmpty()) {
            throw new IllegalStateException("No seeds found. Check your path: " + seedPathStr);
        }

        return seedVectors;
    }

}