| /* |
| * 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.solr.client.solrj.io.eval; |
| |
| import java.io.IOException; |
| import java.util.ArrayList; |
| import java.util.List; |
| import java.util.Map; |
| import java.util.HashMap; |
| |
| import org.apache.commons.math3.ml.clustering.Cluster; |
| import org.apache.commons.math3.ml.distance.DistanceMeasure; |
| import org.apache.commons.math3.ml.distance.EuclideanDistance; |
| import org.apache.solr.client.solrj.io.Tuple; |
| import org.apache.commons.math3.ml.clustering.Clusterable; |
| import org.apache.commons.math3.ml.clustering.DBSCANClusterer; |
| import org.apache.solr.client.solrj.io.stream.expr.StreamExpression; |
| import org.apache.solr.client.solrj.io.stream.expr.StreamFactory; |
| |
| public class DbscanEvaluator extends RecursiveObjectEvaluator implements ManyValueWorker { |
| protected static final long serialVersionUID = 1L; |
| |
| |
| public DbscanEvaluator(StreamExpression expression, StreamFactory factory) throws IOException{ |
| super(expression, factory); |
| } |
| |
| @Override |
| @SuppressWarnings({"unchecked"}) |
| public Object doWork(Object... values) throws IOException { |
| |
| Matrix matrix = null; |
| double e = 0; |
| int minPoints = 1; |
| DistanceMeasure distanceMeasure = new EuclideanDistance(); |
| |
| if(values.length < 3 || values.length > 4) { |
| throw new IOException("The dbscan scan function requires 3 or 4 parameters."); |
| } |
| |
| if(values[0] instanceof Matrix) { |
| matrix = (Matrix)values[0]; |
| } else { |
| throw new IOException("The first parameter for dbscan should be the observation matrix."); |
| } |
| |
| if(values[1] instanceof Number) { |
| e = ((Number)values[1]).doubleValue(); |
| } else { |
| throw new IOException("The second parameter for dbscan should be e."); |
| } |
| |
| if(values[2] instanceof Number) { |
| minPoints = ((Number)values[2]).intValue(); |
| } else { |
| throw new IOException("The third parameter for dbscan should be minPoints."); |
| } |
| |
| if(values.length > 3) { |
| distanceMeasure = (DistanceMeasure)values[3]; |
| } |
| |
| @SuppressWarnings({"rawtypes"}) |
| DBSCANClusterer<ClusterPoint> dbscan = new DBSCANClusterer(e, minPoints, distanceMeasure); |
| List<ClusterPoint> points = new ArrayList<>(); |
| double[][] data = matrix.getData(); |
| List<String> ids = matrix.getRowLabels(); |
| |
| for(int i=0; i<data.length; i++) { |
| double[] vec = data[i]; |
| if(ids != null) { |
| points.add(new ClusterPoint(ids.get(i), vec)); |
| } else { |
| points.add(new ClusterPoint(Integer.toString(i), vec)); |
| } |
| } |
| |
| @SuppressWarnings({"rawtypes"}) |
| Map fields = new HashMap(); |
| |
| fields.put("e", e); |
| fields.put("minPoints", minPoints); |
| fields.put("distance", distanceMeasure.toString()); |
| |
| return new ClusterTuple(fields, dbscan.cluster(points), matrix.getColumnLabels()); |
| } |
| |
| public static class ClusterPoint implements Clusterable { |
| |
| private double[] point; |
| private String id; |
| |
| public ClusterPoint(String id, double[] point) { |
| this.id = id; |
| this.point = point; |
| } |
| |
| public double[] getPoint() { |
| return this.point; |
| } |
| |
| public String getId() { |
| return this.id; |
| } |
| } |
| |
| public static class ClusterTuple extends Tuple { |
| |
| private List<String> columnLabels; |
| private List<Cluster<ClusterPoint>> clusters; |
| |
| public ClusterTuple(@SuppressWarnings({"rawtypes"})Map fields, |
| List<Cluster<ClusterPoint>> clusters, |
| List<String> columnLabels) { |
| super(fields); |
| this.clusters = clusters; |
| this.columnLabels = columnLabels; |
| } |
| |
| public List<String> getColumnLabels() { |
| return this.columnLabels; |
| } |
| |
| public List<Cluster<ClusterPoint>> getClusters() { |
| return this.clusters; |
| } |
| } |
| } |
| |