SOLR-11225: Add cumulativeProbability Stream Evaluator

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

@@ -224,6 +224,7 @@ public class StreamHandler extends RequestHandlerBase implements SolrCoreAware,
         .withFunctionName("kolmogorovSmirnov", KolmogorovSmirnovEvaluator.class)
         .withFunctionName("ks", KolmogorovSmirnovEvaluator.class)
         .withFunctionName("asc", AscEvaluator.class)
+        .withFunctionName("cumulativeProbability", CumulativeProbabilityEvaluator.class)
 
         // Boolean Stream Evaluators
         .withFunctionName("and", AndEvaluator.class)

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

@@ -0,0 +1,67 @@
+/*
+ * 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.distribution.RealDistribution;
+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);
+
+    if(2 != subEvaluators.size()){
+      throw new IOException(String.format(Locale.ROOT,"Invalid expression %s - expecting two values (regression result and a number) but found %d",expression,subEvaluators.size()));
+    }
+  }
+
+  public Number evaluate(Tuple tuple) throws IOException {
+    StreamEvaluator a = subEvaluators.get(0);
+    StreamEvaluator b = subEvaluators.get(1);
+    Number number1 = (Number)b.evaluate(tuple);
+    RealDistribution rd= (RealDistribution)a.evaluate(tuple);
+
+    return rd.cumulativeProbability(number1.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/test/org/apache/solr/client/solrj/io/stream/StreamExpressionTest.java

@@ -5287,6 +5287,23 @@ public class StreamExpressionTest extends SolrCloudTestCase {
   }
 
 
+  @Test
+  public void testCumulativeProbability() throws Exception {
+    String expr = "cumulativeProbability(normalDistribution(500, 40), 500)";
+    ModifiableSolrParams paramsLoc = new ModifiableSolrParams();
+    paramsLoc.set("expr", expr);
+    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);
+    Number number = (Number)tuples.get(0).get("return-value");
+    assertTrue(number.doubleValue() == .5D);
+  }