/**
* 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.clustering.kmeans;
import java.util.Collection;
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.common.iterator.sequencefile.PathFilters;
import org.apache.mahout.common.iterator.sequencefile.PathType;
import org.apache.mahout.common.iterator.sequencefile.SequenceFileDirValueIterable;
final class KMeansUtil {
private KMeansUtil() {
}
/** Configure the mapper with the cluster info */
public static void configureWithClusterInfo(Configuration conf,
Path clusterPath,
Collection<Cluster> clusters) {
for (Writable value :
new SequenceFileDirValueIterable<Writable>(clusterPath, PathType.LIST, PathFilters.partFilter(), conf)) {
Class<? extends Writable> valueClass = value.getClass();
if (valueClass.equals(Cluster.class)) {
// get the cluster info
clusters.add((Cluster) value);
} else if (valueClass.equals(Canopy.class)) {
// get the cluster info
Canopy canopy = (Canopy) value;
clusters.add(new Cluster(canopy.getCenter(), canopy.getId(), canopy.getMeasure()));
} else {
throw new IllegalStateException("Bad value class: " + valueClass);
}
}
}
}