/*********************************************************************************************************************** * Copyright (C) 2010-2013 by the Stratosphere project (http://stratosphere.eu) * * 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 eu.stratosphere.test.recordJobs.kmeans.udfs; import java.io.Serializable; import java.util.Collection; import eu.stratosphere.api.java.record.functions.FunctionAnnotation.ConstantFieldsFirst; import eu.stratosphere.api.java.record.functions.MapFunction; import eu.stratosphere.configuration.Configuration; import eu.stratosphere.types.DoubleValue; import eu.stratosphere.types.IntValue; import eu.stratosphere.types.Record; import eu.stratosphere.util.Collector; /** * Cross PACT computes the distance of all data points to all cluster * centers. */ @ConstantFieldsFirst({0,1}) public class ComputeDistanceParameterized extends MapFunction implements Serializable { private static final long serialVersionUID = 1L; private final DoubleValue distance = new DoubleValue(); private Collection<Record> clusterCenters; @Override public void open(Configuration parameters) throws Exception { this.clusterCenters = this.getRuntimeContext().getBroadcastVariable("centers"); } /** * Computes the distance of one data point to one cluster center. * * Output Format: * 0: pointID * 1: pointVector * 2: clusterID * 3: distance */ @Override public void map(Record dataPointRecord, Collector<Record> out) { CoordVector dataPoint = dataPointRecord.getField(1, CoordVector.class); for (Record clusterCenterRecord : this.clusterCenters) { IntValue clusterCenterId = clusterCenterRecord.getField(0, IntValue.class); CoordVector clusterPoint = clusterCenterRecord.getField(1, CoordVector.class); this.distance.setValue(dataPoint.computeEuclidianDistance(clusterPoint)); // add cluster center id and distance to the data point record dataPointRecord.setField(2, clusterCenterId); dataPointRecord.setField(3, this.distance); out.collect(dataPointRecord); } } }