SOLR-11398: Add weibullDistribution Stream Evaluator

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

@@ -301,12 +301,12 @@ public class StreamHandler extends RequestHandlerBase implements SolrCoreAware,
         .withFunctionName("movingMedian", MovingMedianEvaluator.class)
         .withFunctionName("monteCarlo", MonteCarloEvaluator.class)
         .withFunctionName("constantDistribution", ConstantDistributionEvaluator.class)
+        .withFunctionName("weibullDistribution", WeibullDistributionEvaluator.class)
+        .withFunctionName("mean", MeanEvaluator.class)
 
         // Boolean Stream Evaluators
 
-
-
-                .withFunctionName("and", AndEvaluator.class)
+        .withFunctionName("and", AndEvaluator.class)
         .withFunctionName("eor", ExclusiveOrEvaluator.class)
         .withFunctionName("eq", EqualToEvaluator.class)
         .withFunctionName("gt", GreaterThanEvaluator.class)

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

@@ -0,0 +1,57 @@
+/*
+ * 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.List;
+import java.util.Locale;
+
+import org.apache.solr.client.solrj.io.stream.expr.StreamExpression;
+import org.apache.solr.client.solrj.io.stream.expr.StreamFactory;
+import org.apache.commons.math3.stat.StatUtils;
+
+
+public class MeanEvaluator extends RecursiveObjectEvaluator implements OneValueWorker {
+  protected static final long serialVersionUID = 1L;
+
+  public MeanEvaluator(StreamExpression expression, StreamFactory factory) throws IOException{
+    super(expression, factory);
+
+    if(1 != containedEvaluators.size()){
+      throw new IOException(String.format(Locale.ROOT,"Invalid expression %s - expecting exactly 1 value but found %d",expression,containedEvaluators.size()));
+    }
+  }
+
+  @Override
+  public Object doWork(Object value) throws IOException{
+    if(null == value){
+      throw new IOException(String.format(Locale.ROOT, "Unable to find %s(...) because the value is null", constructingFactory.getFunctionName(getClass())));
+    }
+    else if(value instanceof List){
+      List<Number> c = (List<Number>) value;
+      double[] data = new double[c.size()];
+      for(int i=0; i< c.size(); i++) {
+        data[i] = c.get(i).doubleValue();
+      }
+
+      return StatUtils.mean(data);
+    }
+    else{
+      throw new IOException(String.format(Locale.ROOT, "Unable to find %s(...) because the value is not a collection, instead a %s was found", constructingFactory.getFunctionName(getClass()), value.getClass().getSimpleName()));
+    }
+  }
+}

solr/solrj/src/java/org/apache/solr/client/solrj/io/eval/WeibullDistributionEvaluator.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.WeibullDistribution;
+import org.apache.solr.client.solrj.io.stream.expr.StreamExpression;
+import org.apache.solr.client.solrj.io.stream.expr.StreamFactory;
+
+public class WeibullDistributionEvaluator extends RecursiveNumericEvaluator implements TwoValueWorker {
+
+  private static final long serialVersionUID = 1;
+
+  public WeibullDistributionEvaluator(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 shape = (Number)first;
+    Number scale = (Number)second;
+
+    return new WeibullDistribution(shape.doubleValue(), scale.doubleValue());
+  }
+}

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

@@ -6552,6 +6552,53 @@ public class StreamExpressionTest extends SolrCloudTestCase {
   }
 
 
+  @Test
+  public void testWeibullDistribution() throws Exception {
+    String cexpr = "let(echo=true, " +
+                       "a=percentile(sample(weibullDistribution(1, 10),5000), 50), " +
+                       "b=percentile(sample(weibullDistribution(1, 50),5000), 50), " +
+                       "c=percentile(sample(weibullDistribution(1, 100),5000), 50)," +
+                       "d=percentile(sample(weibullDistribution(4, 10),5000), 50)," +
+                       "e=percentile(sample(weibullDistribution(8, 10),5000), 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 a = (Number)tuples.get(0).get("a");
+    Number b = (Number)tuples.get(0).get("b");
+    Number c = (Number)tuples.get(0).get("c");
+    Number d = (Number)tuples.get(0).get("d");
+    Number e = (Number)tuples.get(0).get("e");
+    assertTrue(a.doubleValue() < b.doubleValue());
+    assertTrue(b.doubleValue() < c.doubleValue());
+    assertTrue(a.doubleValue() < d.doubleValue());
+    assertTrue(d.doubleValue() < e.doubleValue());
+  }
+
+
+  @Test
+  public void testMean() throws Exception {
+    String cexpr = "mean(array(1,2,3,4,5))";
+    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);
+    Number mean = (Number)tuples.get(0).get("return-value");
+    assertEquals(mean.doubleValue(), 3.0D, 0.0D);
+  }
+
+
   @Test
   public void testScale() throws Exception {
     UpdateRequest updateRequest = new UpdateRequest();