SOLR-11697: Add geometricDistribution Stream Evaluator

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

@@ -279,6 +279,7 @@ public class StreamHandler extends RequestHandlerBase implements SolrCoreAware,
         .withFunctionName("diff", TimeDifferencingEvaluator.class)
         .withFunctionName("corrPValues", CorrelationSignificanceEvaluator.class)
         .withFunctionName("normalizeSum", NormalizeSumEvaluator.class)
+        .withFunctionName("geometricDistribution", GeometricDistributionEvaluator.class)
 
         // Boolean Stream Evaluators
 

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

@@ -0,0 +1,44 @@
+/*
+ * 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.GeometricDistribution;
+import org.apache.solr.client.solrj.io.stream.expr.StreamExpression;
+import org.apache.solr.client.solrj.io.stream.expr.StreamFactory;
+
+public class GeometricDistributionEvaluator extends RecursiveNumericEvaluator implements OneValueWorker {
+
+  private static final long serialVersionUID = 1;
+
+  public GeometricDistributionEvaluator(StreamExpression expression, StreamFactory factory) throws IOException {
+    super(expression, factory);
+  }
+
+  @Override
+  public Object doWork(Object first) throws IOException{
+    if(null == first){
+      throw new IOException(String.format(Locale.ROOT,"Invalid expression %s - null found for the first value",toExpression(constructingFactory)));
+    }
+
+    Number prob = (Number)first;
+
+    return new GeometricDistribution(prob.doubleValue());
+  }
+}

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

@@ -39,6 +39,6 @@ public class PoissonDistributionEvaluator extends RecursiveNumericEvaluator impl
 
     Number mean = (Number)first;
 
-    return new PoissonDistribution(mean.intValue());
+    return new PoissonDistribution(mean.doubleValue());
   }
 }

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

@@ -6765,6 +6765,45 @@ public class StreamExpressionTest extends SolrCloudTestCase {
     assertEquals(cprob.doubleValue(), 0.5265621985303708, 0.0);
   }
 
+  @Test
+  public void testGeometricDistribution() throws Exception {
+    String cexpr = "let(a=geometricDistribution(.2)," +
+        "               b=geometricDistribution(.5)," +
+        "               c=geometricDistribution(.8)," +
+        "               d=sample(a, 10000)," +
+        "               e=sample(b, 10000)," +
+        "               f=sample(c, 10000)," +
+        "               g=freqTable(d)," +
+        "               h=freqTable(e)," +
+        "               i=freqTable(f)," +
+        "               tuple(g=g, h=h, i=i))";
+
+    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);
+
+    List<Map> listg = (List<Map>)tuples.get(0).get("g");
+    Map mapg = listg.get(0);
+    double pctg = (double) mapg.get("pct");
+    assertEquals(pctg, .2, .02 );
+
+    List<Map> listh = (List<Map>)tuples.get(0).get("h");
+    Map maph = listh.get(0);
+    double pcth = (double)maph.get("pct");
+    assertEquals(pcth, .5, .02 );
+
+    List<Map> listi = (List<Map>)tuples.get(0).get("i");
+    Map mapi = listi.get(0);
+    double pcti = (double)mapi.get("pct");
+    assertEquals(pcti, .8, .02 );
+  }
+
   @Test
   public void testBinomialDistribution() throws Exception {
     String cexpr = "let(a=binomialDistribution(100, .50)," +