SOLR-11241: Add discrete counting and probability Stream Evaluators

lucene/ivy-versions.properties

@@ -94,7 +94,7 @@ org.apache.calcite.version = 1.13.0
 /org.apache.commons/commons-compress = 1.11
 /org.apache.commons/commons-exec = 1.3
 /org.apache.commons/commons-lang3 = 3.6
-/org.apache.commons/commons-math3 = 3.4.1
+/org.apache.commons/commons-math3 = 3.6.1
 
 org.apache.curator.version = 2.8.0
 /org.apache.curator/curator-client = ${org.apache.curator.version}

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

@@ -29,6 +29,7 @@ import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
 
+import org.apache.commons.math3.distribution.PoissonDistribution;
 import org.apache.solr.client.solrj.io.ModelCache;
 import org.apache.solr.client.solrj.io.SolrClientCache;
 import org.apache.solr.client.solrj.io.Tuple;
@@ -249,6 +250,7 @@ public class StreamHandler extends RequestHandlerBase implements SolrCoreAware,
         .withFunctionName("copyOfRange", CopyOfRangeEvaluator.class)
         .withFunctionName("copyOf", CopyOfEvaluator.class)
         .withFunctionName("cov", CovarianceEvaluator.class)
+        .withFunctionName("corr", CorrelationEvaluator.class)
         .withFunctionName("describe", DescribeEvaluator.class)
         .withFunctionName("distance", EuclideanDistanceEvaluator.class)
         .withFunctionName("empiricalDistribution", EmpiricalDistributionEvaluator.class)
@@ -281,8 +283,17 @@ public class StreamHandler extends RequestHandlerBase implements SolrCoreAware,
         .withFunctionName("ebeDivide", EBEDivideEvaluator.class)
         .withFunctionName("dotProduct", DotProductEvaluator.class)
         .withFunctionName("cosineSimilarity", CosineSimilarityEvaluator.class)
+        .withFunctionName("freqTable", FrequencyTableEvaluator.class)
+        .withFunctionName("uniformIntegerDistribution", UniformIntegerDistributionEvaluator.class)
+        .withFunctionName("binomialDistribution", BinomialDistributionEvaluator.class)
+        .withFunctionName("poissonDistribution", PoissonDistributionEvaluator.class)
+        .withFunctionName("enumeratedDistribution", EnumeratedDistributionEvaluator.class)
+        .withFunctionName("probability", ProbabilityEvaluator.class)
 
         // Boolean Stream Evaluators
+
+
+
                 .withFunctionName("and", AndEvaluator.class)
         .withFunctionName("eor", ExclusiveOrEvaluator.class)
         .withFunctionName("eq", EqualToEvaluator.class)
@@ -331,7 +342,6 @@ public class StreamHandler extends RequestHandlerBase implements SolrCoreAware,
         .withFunctionName("cbrt", CubedRootEvaluator.class)
         .withFunctionName("coalesce", CoalesceEvaluator.class)
         .withFunctionName("uuid", UuidEvaluator.class)
-        .withFunctionName("corr", CorrelationEvaluator.class)
 
         // Conditional Stream Evaluators
         .withFunctionName("if", IfThenElseEvaluator.class)

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

@@ -0,0 +1,48 @@
+/*
+ * 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.BinomialDistribution;
+import org.apache.solr.client.solrj.io.stream.expr.StreamExpression;
+import org.apache.solr.client.solrj.io.stream.expr.StreamFactory;
+
+public class BinomialDistributionEvaluator extends RecursiveNumericEvaluator implements TwoValueWorker {
+
+  private static final long serialVersionUID = 1;
+
+  public BinomialDistributionEvaluator(StreamExpression expression, StreamFactory factory) throws IOException {
+    super(expression, factory);
+  }
+
+  @Override
+  public Object doWork(Object first, Object second) throws IOException{
+    if(null == first){
+      throw new IOException(String.format(Locale.ROOT,"Invalid expression %s - null found for the first value",toExpression(constructingFactory)));
+    }
+    if(null == second){
+      throw new IOException(String.format(Locale.ROOT,"Invalid expression %s - null found for the second value",toExpression(constructingFactory)));
+    }
+
+    Number numberOfTrials = (Number)first;
+    Number successProb = (Number)second;
+
+    return new BinomialDistribution(numberOfTrials.intValue(), successProb.doubleValue());
+  }
+}

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

@@ -20,6 +20,7 @@ import java.io.IOException;
 import java.util.Locale;
 
 import org.apache.commons.math3.distribution.RealDistribution;
+import org.apache.commons.math3.distribution.IntegerDistribution;
 import org.apache.solr.client.solrj.io.stream.expr.StreamExpression;
 import org.apache.solr.client.solrj.io.stream.expr.StreamFactory;
 
@@ -38,17 +39,21 @@ public class CumulativeProbabilityEvaluator extends RecursiveObjectEvaluator imp
     if(null == second){
       throw new IOException(String.format(Locale.ROOT,"Invalid expression %s - null found for the second value",toExpression(constructingFactory)));
     }
-    if(!(first instanceof RealDistribution)){
+    if(!(first instanceof RealDistribution) && !(first instanceof IntegerDistribution)){
-      throw new IOException(String.format(Locale.ROOT,"Invalid expression %s - found type %s for the first value, expecting a RealDistribution",toExpression(constructingFactory), first.getClass().getSimpleName()));
+      throw new IOException(String.format(Locale.ROOT,"Invalid expression %s - found type %s for the first value, expecting a real or integer Distribution",toExpression(constructingFactory), first.getClass().getSimpleName()));
     }
     if(!(second instanceof Number)){
       throw new IOException(String.format(Locale.ROOT,"Invalid expression %s - found type %s for the second value, expecting a Number",toExpression(constructingFactory), first.getClass().getSimpleName()));
     }
 
-    RealDistribution rd = (RealDistribution)first;
+    if(first instanceof  RealDistribution) {
-    Number predictOver = (Number)second;
+      RealDistribution rd = (RealDistribution) first;
-    
+      Number predictOver = (Number) second;
       return rd.cumulativeProbability(predictOver.doubleValue());
+    } else {
+      IntegerDistribution id = (IntegerDistribution) first;
+      Number predictOver = (Number) second;
+      return id.cumulativeProbability(predictOver.intValue());
+    }
   }
-  
 }

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

@@ -0,0 +1,45 @@
+/*
+ * 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.math.BigDecimal;
+import java.util.List;
+import java.util.Locale;
+
+import org.apache.commons.math3.distribution.EnumeratedIntegerDistribution;
+import org.apache.solr.client.solrj.io.stream.expr.StreamExpression;
+import org.apache.solr.client.solrj.io.stream.expr.StreamFactory;
+
+public class EnumeratedDistributionEvaluator extends RecursiveNumericEvaluator implements OneValueWorker {
+
+  private static final long serialVersionUID = 1;
+
+  public EnumeratedDistributionEvaluator(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)));
+    }
+
+     int[] samples = ((List)first).stream().mapToInt(value -> ((BigDecimal) value).intValue()).toArray();
+     return new EnumeratedIntegerDistribution(samples);
+  }
+}

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

@@ -0,0 +1,86 @@
+/*
+ * 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.Arrays;
+import java.util.HashMap;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Locale;
+import java.util.Map;
+
+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.solr.client.solrj.io.Tuple;
+import org.apache.solr.client.solrj.io.stream.expr.StreamExpression;
+import org.apache.solr.client.solrj.io.stream.expr.StreamFactory;
+
+public class FrequencyTableEvaluator extends RecursiveNumericEvaluator implements ManyValueWorker {
+  protected static final long serialVersionUID = 1L;
+
+  public FrequencyTableEvaluator(StreamExpression expression, StreamFactory factory) throws IOException{
+    super(expression, factory);
+
+    if(containedEvaluators.size() < 1){
+      throw new IOException(String.format(Locale.ROOT,"Invalid expression %s - expecting at least one value but found %d",expression,containedEvaluators.size()));
+    }
+  }
+
+  @Override
+  public Object doWork(Object... values) throws IOException {
+    if(Arrays.stream(values).anyMatch(item -> null == item)){
+      return null;
+    }
+
+    List<?> sourceValues;
+
+    if(values.length == 1){
+      sourceValues = values[0] instanceof List<?> ? (List<?>)values[0] : Arrays.asList(values[0]);
+    }
+    else
+    {
+      throw new IOException(String.format(Locale.ROOT,"Invalid expression %s - expecting at least one value but found %d",toExpression(constructingFactory),containedEvaluators.size()));
+    }
+
+    Frequency frequency = new Frequency();
+
+    for(Object o : sourceValues) {
+      Number number = (Number)o;
+      frequency.addValue(number.longValue());
+    }
+
+    List<Tuple> histogramBins = new ArrayList<>();
+
+    Iterator iterator = frequency.valuesIterator();
+
+    while(iterator.hasNext()){
+      Long value = (Long)iterator.next();
+      Map<String,Number> map = new HashMap<>();
+      map.put("value", value.longValue());
+      map.put("count", frequency.getCount(value));
+      map.put("cumFreq", frequency.getCumFreq(value));
+      map.put("cumPct", frequency.getCumPct(value));
+      map.put("pct", frequency.getPct(value));
+      histogramBins.add(new Tuple(map));
+    }
+    return histogramBins;
+  }
+}

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

@@ -26,6 +26,7 @@ import java.util.Map;
 
 import org.apache.commons.math3.random.EmpiricalDistribution;
 import org.apache.commons.math3.stat.descriptive.SummaryStatistics;
+import org.apache.solr.client.solrj.io.Tuple;
 import org.apache.solr.client.solrj.io.stream.expr.StreamExpression;
 import org.apache.solr.client.solrj.io.stream.expr.StreamFactory;
 
@@ -68,7 +69,7 @@ public class HistogramEvaluator extends RecursiveNumericEvaluator implements Man
     EmpiricalDistribution distribution = new EmpiricalDistribution(bins);
     distribution.load(((List<?>)sourceValues).stream().mapToDouble(value -> ((Number)value).doubleValue()).toArray());;
 
-    List<Map<String,Number>> histogramBins = new ArrayList<>();
+    List<Tuple> histogramBins = new ArrayList<>();
     for(SummaryStatistics binSummary : distribution.getBinStats()) {
       Map<String,Number> map = new HashMap<>();
       map.put("max", binSummary.getMax());
@@ -78,7 +79,9 @@ public class HistogramEvaluator extends RecursiveNumericEvaluator implements Man
       map.put("sum", binSummary.getSum());
       map.put("N", binSummary.getN());
       map.put("var", binSummary.getVariance());
-      histogramBins.add(map);
+      map.put("cumProb", distribution.cumulativeProbability(binSummary.getMean()));
+      map.put("prob", distribution.probability(binSummary.getMin(), binSummary.getMax()));
+      histogramBins.add(new Tuple(map));
     }
     
     return histogramBins;

solr/solrj/src/java/org/apache/solr/client/solrj/io/eval/PoissonDistributionEvaluator.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.PoissonDistribution;
+import org.apache.solr.client.solrj.io.stream.expr.StreamExpression;
+import org.apache.solr.client.solrj.io.stream.expr.StreamFactory;
+
+public class PoissonDistributionEvaluator extends RecursiveNumericEvaluator implements OneValueWorker {
+
+  private static final long serialVersionUID = 1;
+
+  public PoissonDistributionEvaluator(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 mean = (Number)first;
+
+    return new PoissonDistribution(mean.intValue());
+  }
+}

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

@@ -0,0 +1,52 @@
+/*
+ * 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.IntegerDistribution;
+import org.apache.solr.client.solrj.io.stream.expr.StreamExpression;
+import org.apache.solr.client.solrj.io.stream.expr.StreamFactory;
+
+public class ProbabilityEvaluator extends RecursiveObjectEvaluator implements TwoValueWorker {
+  protected static final long serialVersionUID = 1L;
+
+  public ProbabilityEvaluator(StreamExpression expression, StreamFactory factory) throws IOException{
+    super(expression, factory);
+  }
+
+  @Override
+  public Object doWork(Object first, Object second) throws IOException{
+    if(null == first){
+      throw new IOException(String.format(Locale.ROOT,"Invalid expression %s - null found for the first value",toExpression(constructingFactory)));
+    }
+    if(null == second){
+      throw new IOException(String.format(Locale.ROOT,"Invalid expression %s - null found for the second value",toExpression(constructingFactory)));
+    }
+    if(!(first instanceof IntegerDistribution)){
+      throw new IOException(String.format(Locale.ROOT,"Invalid expression %s - found type %s for the first value, expecting a IntegerDistribution",toExpression(constructingFactory), first.getClass().getSimpleName()));
+    }
+    if(!(second instanceof Number)){
+      throw new IOException(String.format(Locale.ROOT,"Invalid expression %s - found type %s for the second value, expecting a Number",toExpression(constructingFactory), first.getClass().getSimpleName()));
+    }
+
+    IntegerDistribution d = (IntegerDistribution) first;
+    Number predictOver = (Number) second;
+    return d.probability(predictOver.intValue());
+  }
+}

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

@@ -22,6 +22,7 @@ import java.util.Arrays;
 import java.util.Locale;
 import java.util.stream.Collectors;
 
+import org.apache.commons.math3.distribution.IntegerDistribution;
 import org.apache.commons.math3.distribution.RealDistribution;
 import org.apache.solr.client.solrj.io.stream.expr.StreamExpression;
 import org.apache.solr.client.solrj.io.stream.expr.StreamFactory;
@@ -42,16 +43,19 @@ public class SampleEvaluator extends RecursiveObjectEvaluator implements TwoValu
     if(null == second){
       throw new IOException(String.format(Locale.ROOT,"Invalid expression %s - null found for the second value",toExpression(constructingFactory)));
     }
-    if(!(first instanceof RealDistribution)){
+    if(!(first instanceof RealDistribution) && !(first instanceof IntegerDistribution)){
-      throw new IOException(String.format(Locale.ROOT,"Invalid expression %s - found type %s for the first value, expecting a RealDistribution",toExpression(constructingFactory), first.getClass().getSimpleName()));
+      throw new IOException(String.format(Locale.ROOT,"Invalid expression %s - found type %s for the first value, expecting a Real or Integer Distribution",toExpression(constructingFactory), first.getClass().getSimpleName()));
     }
     if(!(second instanceof Number)){
       throw new IOException(String.format(Locale.ROOT,"Invalid expression %s - found type %s for the second value, expecting a Number",toExpression(constructingFactory), first.getClass().getSimpleName()));
     }
 
-    RealDistribution realDistribution = (RealDistribution)first;
+    if(first instanceof RealDistribution) {
-    
+      RealDistribution realDistribution = (RealDistribution) first;
-    return Arrays.stream(realDistribution.sample(((Number)second).intValue())).mapToObj(item -> item).collect(Collectors.toList());    
+      return Arrays.stream(realDistribution.sample(((Number) second).intValue())).mapToObj(item -> item).collect(Collectors.toList());
+    } else {
+      IntegerDistribution integerDistribution = (IntegerDistribution) first;
+      return Arrays.stream(integerDistribution.sample(((Number) second).intValue())).mapToObj(item -> item).collect(Collectors.toList());
+    }
   }
-
 }

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

@@ -0,0 +1,48 @@
+/*
+ * 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.UniformIntegerDistribution;
+import org.apache.solr.client.solrj.io.stream.expr.StreamExpression;
+import org.apache.solr.client.solrj.io.stream.expr.StreamFactory;
+
+public class UniformIntegerDistributionEvaluator extends RecursiveNumericEvaluator implements TwoValueWorker {
+
+  private static final long serialVersionUID = 1;
+
+  public UniformIntegerDistributionEvaluator(StreamExpression expression, StreamFactory factory) throws IOException {
+    super(expression, factory);
+  }
+
+  @Override
+  public Object doWork(Object first, Object second) throws IOException{
+    if(null == first){
+      throw new IOException(String.format(Locale.ROOT,"Invalid expression %s - null found for the first value",toExpression(constructingFactory)));
+    }
+    if(null == second){
+      throw new IOException(String.format(Locale.ROOT,"Invalid expression %s - null found for the second value",toExpression(constructingFactory)));
+    }
+
+    Number lower = (Number)first;
+    Number upper = (Number)second;
+
+    return new UniformIntegerDistribution(lower.intValue(), upper.intValue());
+  }
+}

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

@@ -6155,6 +6155,48 @@ public class StreamExpressionTest extends SolrCloudTestCase {
     assertTrue(out.get(5).intValue() == 2);
   }
 
+
+  @Test
+  public void testFreqTable() throws Exception {
+    String cexpr = "freqTable(array(2,4,6,8,10,12,12,4,8,8,8,2))";
+    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<String,Number>> out = (List<Map<String, Number>>)tuples.get(0).get("return-value");
+    assertTrue(out.size() == 6);
+    Map<String, Number> bucket = out.get(0);
+    assertEquals(bucket.get("value").longValue(), 2);
+    assertEquals(bucket.get("count").longValue(), 2);
+
+    bucket = out.get(1);
+    assertEquals(bucket.get("value").longValue(), 4);
+    assertEquals(bucket.get("count").longValue(), 2);
+
+    bucket = out.get(2);
+    assertEquals(bucket.get("value").longValue(), 6);
+    assertEquals(bucket.get("count").longValue(), 1);
+
+    bucket = out.get(3);
+    assertEquals(bucket.get("value").longValue(), 8);
+    assertEquals(bucket.get("count").longValue(), 4);
+
+    bucket = out.get(4);
+    assertEquals(bucket.get("value").longValue(), 10);
+    assertEquals(bucket.get("count").longValue(), 1);
+
+    bucket = out.get(5);
+    assertEquals(bucket.get("value").longValue(), 12);
+    assertEquals(bucket.get("count").longValue(), 2);
+  }
+
+
+
   @Test
   public void testCosineSimilarity() throws Exception {
     String cexpr = "cosineSimilarity(array(2,4,6,8),array(1,1,3,4))";
@@ -6171,7 +6213,109 @@ public class StreamExpressionTest extends SolrCloudTestCase {
     assertTrue(cs.doubleValue() == 0.9838197164968291);
   }
 
+  @Test
+  public void testPoissonDistribution() throws Exception {
+    String cexpr = "let(a=poissonDistribution(100)," +
+        "               b=sample(a, 10000)," +
+        "               tuple(d=describe(b), " +
+        "                     p=probability(a, 100), " +
+        "                     c=cumulativeProbability(a, 100)))";
 
+    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);
+    Map map = (Map)tuples.get(0).get("d");
+    Number mean = (Number)map.get("mean");
+    Number var = (Number)map.get("var");
+    //The mean and variance should be almost the same for poisson distribution
+    assertEquals(mean.doubleValue(), var.doubleValue(), 3.0);
+    Number prob = (Number)tuples.get(0).get("p");
+    assertEquals(prob.doubleValue(), 0.03986099680914713, 0.0);
+    Number cprob = (Number)tuples.get(0).get("c");
+    assertEquals(cprob.doubleValue(), 0.5265621985303708, 0.0);
+  }
+
+  @Test
+  public void testBinomialDistribution() throws Exception {
+    String cexpr = "let(a=binomialDistribution(100, .50)," +
+        "               b=sample(a, 10000)," +
+        "               tuple(d=describe(b), " +
+        "                     p=probability(a, 50), " +
+        "                     c=cumulativeProbability(a, 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);
+    Number prob = (Number)tuples.get(0).get("p");
+    assertEquals(prob.doubleValue(),0.07958923738717877, 0.0);
+    Number cprob = (Number)tuples.get(0).get("c");
+    assertEquals(cprob.doubleValue(), 0.5397946186935851, 0.0);
+  }
+
+  @Test
+  public void testUniformIntegerDistribution() throws Exception {
+    String cexpr = "let(a=uniformIntegerDistribution(1, 10)," +
+        "               b=sample(a, 10000)," +
+        "               tuple(d=describe(b), " +
+        "                     p=probability(a, 5), " +
+        "                     c=cumulativeProbability(a, 5)))";
+
+    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);
+    Map map = (Map)tuples.get(0).get("d");
+    Number N = (Number)map.get("N");
+    assertEquals(N.intValue(), 10000);
+    Number prob = (Number)tuples.get(0).get("p");
+    assertEquals(prob.doubleValue(), 0.1, 0.0);
+    Number cprob = (Number)tuples.get(0).get("c");
+    assertEquals(cprob.doubleValue(), 0.5, 0.0);
+  }
+
+  @Test
+  public void testEnumeratedDistribution() throws Exception {
+    String cexpr = "let(a=uniformIntegerDistribution(1, 10)," +
+        "               b=sample(a, 10000)," +
+        "               c=enumeratedDistribution(b),"+
+        "               tuple(d=describe(b), " +
+        "                     p=probability(c, 5), " +
+        "                     c=cumulativeProbability(c, 5)))";
+
+    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);
+    Map map = (Map)tuples.get(0).get("d");
+    Number N = (Number)map.get("N");
+    assertEquals(N.intValue(), 10000);
+    Number prob = (Number)tuples.get(0).get("p");
+    assertEquals(prob.doubleValue(), 0.1, 0.07);
+    Number cprob = (Number)tuples.get(0).get("c");
+    assertEquals(cprob.doubleValue(), 0.5, 0.07);
+  }
 
   @Test
   public void testDotProduct() throws Exception {