SOLR-13589: Allow zplot to visualize clusters and convex hulls

solr/solrj/src/java/org/apache/solr/client/solrj/io/Lang.java

@@ -290,6 +290,7 @@ public class Lang {
         .withFunctionName("notNull", NotNullEvaluator.class)
         .withFunctionName("isNull", IsNullEvaluator.class)
         .withFunctionName("matches", MatchesEvaluator.class)
+        .withFunctionName("projectToBorder", ProjectToBorderEvaluator.class)
 
         // Boolean Stream Evaluators
 

solr/solrj/src/java/org/apache/solr/client/solrj/io/eval/KmeansEvaluator.java

@@ -78,7 +78,11 @@ public class KmeansEvaluator extends RecursiveObjectEvaluator implements TwoValu
 
     for(int i=0; i<data.length; i++) {
       double[] vec = data[i];
-      points.add(new ClusterPoint(ids.get(i), vec));
+      if(ids != null) {
+        points.add(new ClusterPoint(ids.get(i), vec));
+      } else {
+        points.add(new ClusterPoint(Integer.toString(i), vec));
+      }
     }
 
     Map fields = new HashMap();

solr/solrj/src/java/org/apache/solr/client/solrj/io/eval/ProjectToBorderEvaluator.java

@@ -0,0 +1,65 @@
+/*
+ * 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.Locale;
+
+import org.apache.commons.math3.geometry.euclidean.twod.Euclidean2D;
+import org.apache.commons.math3.geometry.euclidean.twod.hull.ConvexHull2D;
+import org.apache.commons.math3.geometry.euclidean.twod.Vector2D;
+import org.apache.commons.math3.geometry.partitioning.BoundaryProjection;
+import org.apache.commons.math3.geometry.partitioning.Region;
+import org.apache.solr.client.solrj.io.stream.expr.StreamExpression;
+import org.apache.solr.client.solrj.io.stream.expr.StreamFactory;
+
+public class ProjectToBorderEvaluator extends RecursiveObjectEvaluator implements TwoValueWorker {
+  private static final long serialVersionUID = 1;
+
+  public ProjectToBorderEvaluator(StreamExpression expression, StreamFactory factory) throws IOException {
+    super(expression, factory);
+  }
+
+  @Override
+  public Object doWork(Object value1, Object value2) throws IOException {
+    if(!(value1 instanceof ConvexHull2D)){
+      throw new IOException(String.format(Locale.ROOT,"Invalid expression %s - found type %s for value, expecting a ConvexHull2D",toExpression(constructingFactory), value1.getClass().getSimpleName()));
+    }
+
+    if(!(value2 instanceof Matrix)){
+      throw new IOException(String.format(Locale.ROOT,"Invalid expression %s - found type %s for value, expecting a Matrix",toExpression(constructingFactory), value2.getClass().getSimpleName()));
+    }
+
+    ConvexHull2D convexHull2D = (ConvexHull2D)value1;
+    Matrix matrix = (Matrix)value2;
+    double[][] data = matrix.getData();
+    Region<Euclidean2D> region = convexHull2D.createRegion();
+    double[][] borderPoints = new double[data.length][2];
+    int i = 0;
+    for(double[] row : data) {
+      BoundaryProjection<Euclidean2D> boundaryProjection = region.projectToBoundary(new Vector2D(row));
+      Vector2D point = (Vector2D)boundaryProjection.getProjected();
+      borderPoints[i][0] = point.getX();
+      borderPoints[i][1] = point.getY();
+      i++;
+    }
+
+    return new Matrix(borderPoints);
+
+  }
+}

solr/solrj/src/java/org/apache/solr/client/solrj/io/stream/ZplotStream.java

@@ -27,12 +27,15 @@ import java.util.Set;
 
 import org.apache.commons.math3.distribution.IntegerDistribution;
 import org.apache.commons.math3.distribution.RealDistribution;
+import org.apache.commons.math3.geometry.Point;
+import org.apache.commons.math3.ml.clustering.CentroidCluster;
 import org.apache.commons.math3.random.EmpiricalDistribution;
 import org.apache.commons.math3.stat.Frequency;
 import org.apache.commons.math3.stat.descriptive.SummaryStatistics;
 import org.apache.commons.math3.util.Precision;
 import org.apache.solr.client.solrj.io.Tuple;
 import org.apache.solr.client.solrj.io.comp.StreamComparator;
+import org.apache.solr.client.solrj.io.eval.KmeansEvaluator;
 import org.apache.solr.client.solrj.io.eval.StreamEvaluator;
 import org.apache.solr.client.solrj.io.stream.expr.Explanation;
 import org.apache.solr.client.solrj.io.stream.expr.Explanation.ExpressionType;
@@ -126,6 +129,7 @@ public class ZplotStream extends TupleStream implements Expressible {
     int columns = 0;
     boolean table = false;
     boolean distribution = false;
+    boolean clusters = false;
     for(Map.Entry<String, Object> entry : entries) {
       ++columns;
 
@@ -134,6 +138,8 @@ public class ZplotStream extends TupleStream implements Expressible {
         table = true;
       } else if(name.equals("dist")) {
         distribution = true;
+      } else if(name.equals("clusters")) {
+        clusters = true;
       }
 
       Object o = entry.getValue();
@@ -181,7 +187,7 @@ public class ZplotStream extends TupleStream implements Expressible {
     //Load the values into tuples
 
     List<Tuple> outTuples = new ArrayList();
-    if(!table && !distribution) {
+    if(!table && !distribution && !clusters) {
       //Handle the vectors
       for (int i = 0; i < numTuples; i++) {
         Tuple tuple = new Tuple(new HashMap());
@@ -194,13 +200,28 @@ public class ZplotStream extends TupleStream implements Expressible {
       }
 
       //Generate the x axis if the tuples contain y and not x
-      if(outTuples.get(0).fields.containsKey("y") && !outTuples.get(0).fields.containsKey("x")) {
+      if (outTuples.get(0).fields.containsKey("y") && !outTuples.get(0).fields.containsKey("x")) {
         int x = 0;
-        for(Tuple tuple : outTuples) {
+        for (Tuple tuple : outTuples) {
           tuple.put("x", x++);
         }
       }
-
+    } else if(clusters) {
+      Object o = evaluated.get("clusters");
+      KmeansEvaluator.ClusterTuple ct = (KmeansEvaluator.ClusterTuple)o;
+      List<CentroidCluster<KmeansEvaluator.ClusterPoint>> cs = ct.getClusters();
+      int clusterNum = 0;
+      for(CentroidCluster<KmeansEvaluator.ClusterPoint> c : cs) {
+        clusterNum++;
+        List<KmeansEvaluator.ClusterPoint> points = c.getPoints();
+        for(KmeansEvaluator.ClusterPoint p : points) {
+          Tuple tuple = new Tuple(new HashMap());
+          tuple.put("x", p.getPoint()[0]);
+          tuple.put("y", p.getPoint()[1]);
+          tuple.put("cluster", "cluster"+clusterNum);
+          outTuples.add(tuple);
+        }
+      }
     } else if(distribution) {
       Object o = evaluated.get("dist");
       if(o instanceof RealDistribution) {

solr/solrj/src/test/org/apache/solr/client/solrj/io/TestLang.java

@@ -76,7 +76,7 @@ public class TestLang extends SolrTestCase {
       "getAmplitude", "getPhase", "getAngularFrequency", "enclosingDisk", "getCenter", "getRadius",
       "getSupportPoints", "pairSort", "log10", "plist", "recip", "pivot", "ltrim", "rtrim", "export",
       "zplot", "natural", "repeat", "movingMAD", "hashRollup", "noop", "var", "stddev", "recNum", "isNull",
-      "notNull", "matches"};
+      "notNull", "matches", "projectToBorder"};
 
   @Test
   public void testLang() {

solr/solrj/src/test/org/apache/solr/client/solrj/io/stream/MathExpressionTest.java

@@ -407,7 +407,8 @@ public class MathExpressionTest extends SolrCloudTestCase {
         "              e=getVertices(d)," +
         "              f=getArea(d)," +
         "              g=getBoundarySize(d)," +
-        "              h=getBaryCenter(d))";
+        "              h=getBaryCenter(d)," +
+        "              i=projectToBorder(d, matrix(array(99.11076410926444, 109.5441846957560))))";
     ModifiableSolrParams paramsLoc = new ModifiableSolrParams();
     paramsLoc.set("expr", expr);
     paramsLoc.set("qt", "/stream");
@@ -466,6 +467,11 @@ public class MathExpressionTest extends SolrCloudTestCase {
     assertEquals(baryCenter.get(0).doubleValue(), 101.3021125450865, 0.0);
     assertEquals(baryCenter.get(1).doubleValue(), 100.07343616615786, 0.0);
 
+    List<List<Number>> borderPoints = (List<List<Number>>)tuples.get(0).get("i");
+    assertEquals(borderPoints.get(0).get(0).doubleValue(), 100.31316833934775, 0);
+    assertEquals(borderPoints.get(0).get(1).doubleValue(), 115.6639686234851, 0);
+
+
   }
 
   @Test