/**
* 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.similarity;
import com.google.common.collect.Lists;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.Writable;
import org.apache.mahout.clustering.canopy.Canopy;
import org.apache.mahout.clustering.kmeans.Cluster;
import org.apache.mahout.common.iterator.sequencefile.PathFilters;
import org.apache.mahout.common.iterator.sequencefile.PathType;
import org.apache.mahout.common.iterator.sequencefile.SequenceFileDirValueIterable;
import org.apache.mahout.math.NamedVector;
import org.apache.mahout.math.Vector;
import org.apache.mahout.math.VectorWritable;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.util.Collections;
import java.util.List;
final class SeedVectorUtil {
private static final Logger log = LoggerFactory.getLogger(SeedVectorUtil.class);
private SeedVectorUtil() {
}
public static List<NamedVector> loadSeedVectors(Configuration conf) {
String seedPathStr = conf.get(VectorDistanceSimilarityJob.SEEDS_PATH_KEY);
if (seedPathStr == null || seedPathStr.isEmpty()) {
return Collections.emptyList();
}
List<NamedVector> seedVectors = Lists.newArrayList();
long item = 0;
for (Writable value :
new SequenceFileDirValueIterable<Writable>(new Path(seedPathStr),
PathType.LIST,
PathFilters.partFilter(),
conf)) {
Class<? extends Writable> valueClass = value.getClass();
if (valueClass.equals(Cluster.class)) {
// get the cluster info
Cluster cluster = (Cluster) value;
Vector vector = cluster.getCenter();
if (vector instanceof NamedVector) {
seedVectors.add((NamedVector) vector);
} else {
seedVectors.add(new NamedVector(vector, cluster.getIdentifier()));
}
} else if (valueClass.equals(Canopy.class)) {
// get the cluster info
Canopy canopy = (Canopy) value;
Vector vector = canopy.getCenter();
if (vector instanceof NamedVector) {
seedVectors.add((NamedVector) vector);
} else {
seedVectors.add(new NamedVector(vector, canopy.getIdentifier()));
}
} else if (valueClass.equals(Vector.class)) {
Vector vector = (Vector) value;
if (vector instanceof NamedVector) {
seedVectors.add((NamedVector) vector);
} else {
seedVectors.add(new NamedVector(vector, seedPathStr + '.' + item++));
}
} else if (valueClass.equals(VectorWritable.class) || valueClass.isInstance(VectorWritable.class)) {
VectorWritable vw = (VectorWritable) value;
Vector vector = vw.get();
if (vector instanceof NamedVector) {
seedVectors.add((NamedVector) vector);
} else {
seedVectors.add(new NamedVector(vector, seedPathStr + '.' + item++));
}
} else {
throw new IllegalStateException("Bad value class: " + valueClass);
}
}
if (seedVectors.isEmpty()) {
throw new IllegalStateException("No seeds found. Check your path: " + seedPathStr);
}
log.info("Seed Vectors size: {}", seedVectors.size());
return seedVectors;
}
}