SOLR-10696: Add cumulative probability function

solr/core/src/java/org/apache/solr/handler/StreamHandler.java

@@ -187,6 +187,7 @@ public class StreamHandler extends RequestHandlerBase implements SolrCoreAware,
       .withFunctionName("copyOfRange", CopyOfRangeEvaluator.class)
       .withFunctionName("percentile", PercentileEvaluator.class)
       .withFunctionName("empiricalDistribution", EmpiricalDistributionEvaluator.class)
+      .withFunctionName("cumulativeProbability", CumulativeProbabilityEvaluator.class)
       .withFunctionName("describe", DescribeEvaluator.class)
       .withFunctionName("finddelay", FindDelayEvaluator.class)
       .withFunctionName("sequence", SequenceEvaluator.class)

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

@@ -0,0 +1,66 @@
+/*
+ * 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 org.apache.solr.client.solrj.io.Tuple;
+import org.apache.solr.client.solrj.io.stream.expr.Explanation;
+import org.apache.solr.client.solrj.io.stream.expr.Explanation.ExpressionType;
+import org.apache.solr.client.solrj.io.stream.expr.Expressible;
+import org.apache.solr.client.solrj.io.stream.expr.StreamExpression;
+import org.apache.solr.client.solrj.io.stream.expr.StreamExpressionParameter;
+import org.apache.solr.client.solrj.io.stream.expr.StreamFactory;
+
+public class CumulativeProbabilityEvaluator extends ComplexEvaluator implements Expressible {
+
+  private static final long serialVersionUID = 1;
+
+  public CumulativeProbabilityEvaluator(StreamExpression expression, StreamFactory factory) throws IOException {
+    super(expression, factory);
+  }
+
+  public Number evaluate(Tuple tuple) throws IOException {
+
+    if(subEvaluators.size() != 2) {
+      throw new IOException("Cumulative probability expects 2 parameters: an emperical distribution and a number");
+    }
+
+    StreamEvaluator r = subEvaluators.get(0);
+    StreamEvaluator d = subEvaluators.get(1);
+
+    EmpiricalDistributionEvaluator.EmpiricalDistributionTuple e = (EmpiricalDistributionEvaluator.EmpiricalDistributionTuple)r.evaluate(tuple);
+    Number n = (Number)d.evaluate(tuple);
+    return e.percentile(n.doubleValue());
+  }
+
+  @Override
+  public StreamExpressionParameter toExpression(StreamFactory factory) throws IOException {
+    StreamExpression expression = new StreamExpression(factory.getFunctionName(getClass()));
+    return expression;
+  }
+
+  @Override
+  public Explanation toExplanation(StreamFactory factory) throws IOException {
+    return new Explanation(nodeId.toString())
+        .withExpressionType(ExpressionType.EVALUATOR)
+        .withFunctionName(factory.getFunctionName(getClass()))
+        .withImplementingClass(getClass().getName())
+        .withExpression(toExpression(factory).toString());
+  }
+}

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

@@ -17,6 +17,9 @@
 
 package org.apache.solr.client.solrj.io.eval;
 
+import java.text.DecimalFormat;
+import java.text.NumberFormat;
+import java.util.List;
 import java.io.IOException;
 
 import org.apache.solr.client.solrj.io.Tuple;
@@ -26,6 +29,7 @@ import org.apache.solr.client.solrj.io.stream.expr.Expressible;
 import org.apache.solr.client.solrj.io.stream.expr.StreamExpression;
 import org.apache.solr.client.solrj.io.stream.expr.StreamExpressionParameter;
 import org.apache.solr.client.solrj.io.stream.expr.StreamFactory;
+import org.apache.commons.math3.stat.descriptive.rank.Percentile;
 
 public class PercentileEvaluator extends ComplexEvaluator implements Expressible {
 
@@ -36,17 +40,23 @@ public class PercentileEvaluator extends ComplexEvaluator implements Expressible
   }
 
   public Number evaluate(Tuple tuple) throws IOException {
-
     if(subEvaluators.size() != 2) {
-      throw new IOException("Percentile expects 2 parameters: a regression result and a number");
+      throw new IOException("Percentile expects 2 parameters: an array and a number");
     }
 
-    StreamEvaluator r = subEvaluators.get(0);
-    StreamEvaluator d = subEvaluators.get(1);
+    StreamEvaluator colEval = subEvaluators.get(0);
+    List<Number> column = (List<Number>)colEval.evaluate(tuple);
 
-    EmpiricalDistributionEvaluator.EmpiricalDistributionTuple e = (EmpiricalDistributionEvaluator.EmpiricalDistributionTuple)r.evaluate(tuple);
-    Number n = (Number)d.evaluate(tuple);
-    return e.percentile(n.doubleValue());
+    double[] data = new double[column.size()];
+    for(int i=0; i<data.length; i++) {
+      data[i] = column.get(i).doubleValue();
+    }
+
+    Percentile percentile = new Percentile();
+    percentile.setData(data);
+    StreamEvaluator numEval = subEvaluators.get(1);
+    Number num  = (Number)numEval.evaluate(tuple);
+    return percentile.evaluate(num.doubleValue());
   }
 
   @Override

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

@@ -5759,8 +5759,61 @@ public class StreamExpressionTest extends SolrCloudTestCase {
   }
 
 
+
   @Test
-  public void testPercentiles() throws Exception {
+  public void testPercentile() throws Exception {
+    String cexpr = "percentile(array(1,2,3,4,5,6,7,8,9,10,11), 50)";
+    ModifiableSolrParams paramsLoc = new ModifiableSolrParams();
+    paramsLoc.set("expr", cexpr);
+    paramsLoc.set("qt", "/stream");
+
+    String url = cluster.getJettySolrRunners().get(0).getBaseUrl().toString()+"/"+COLLECTIONORALIAS;
+    TupleStream solrStream = new SolrStream(url, paramsLoc);
+
+    StreamContext context = new StreamContext();
+    solrStream.setStreamContext(context);
+    List<Tuple> tuples = getTuples(solrStream);
+    assertTrue(tuples.size() == 1);
+    Tuple tuple = tuples.get(0);
+    double p = tuple.getDouble("return-value");
+    assertEquals(p, 6, 0.0);
+
+
+    cexpr = "percentile(array(11,10,3,4,5,6,7,8,9,2,1), 50)";
+    paramsLoc = new ModifiableSolrParams();
+    paramsLoc.set("expr", cexpr);
+    paramsLoc.set("qt", "/stream");
+
+    solrStream = new SolrStream(url, paramsLoc);
+
+    context = new StreamContext();
+    solrStream.setStreamContext(context);
+    tuples = getTuples(solrStream);
+    assertTrue(tuples.size() == 1);
+    tuple = tuples.get(0);
+    p = tuple.getDouble("return-value");
+    assertEquals(p, 6, 0.0);
+
+    cexpr = "percentile(array(11,10,3,4,5,6,7,8,9,2,1), 20)";
+    paramsLoc = new ModifiableSolrParams();
+    paramsLoc.set("expr", cexpr);
+    paramsLoc.set("qt", "/stream");
+
+    solrStream = new SolrStream(url, paramsLoc);
+
+    context = new StreamContext();
+    solrStream.setStreamContext(context);
+    tuples = getTuples(solrStream);
+    assertTrue(tuples.size() == 1);
+    tuple = tuples.get(0);
+    p = tuple.getDouble("return-value");
+    assertEquals(p, 2.4, 0.001);
+
+  }
+
+
+  @Test
+  public void testCumulativeProbability() throws Exception {
     UpdateRequest updateRequest = new UpdateRequest();
 
     int i=0;
@@ -5773,11 +5826,11 @@ public class StreamExpressionTest extends SolrCloudTestCase {
 
     String expr = "search("+COLLECTIONORALIAS+", q=\"*:*\", fl=\"price_f\", sort=\"price_f asc\", rows=\"200\")";
     String cexpr = "let(a="+expr+", c=col(a, price_f), e=empiricalDistribution(c), " +
-        "tuple(p1=percentile(e, 88), " +
-        "p2=percentile(e, 2), " +
-        "p3=percentile(e, 99), " +
-        "p4=percentile(e, 77), " +
-        "p5=percentile(e, 98)))";
+        "tuple(p1=cumulativeProbability(e, 88), " +
+        "p2=cumulativeProbability(e, 2), " +
+        "p3=cumulativeProbability(e, 99), " +
+        "p4=cumulativeProbability(e, 77), " +
+        "p5=cumulativeProbability(e, 98)))";
 
     ModifiableSolrParams paramsLoc = new ModifiableSolrParams();
     paramsLoc.set("expr", cexpr);