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diff --git a/bigtop-data-generators/bigtop-weatherman/src/main/java/org/apache/bigtop/datagenerators/weatherman/internal/PrecipitationSampler.java b/bigtop-data-generators/bigtop-weatherman/src/main/java/org/apache/bigtop/datagenerators/weatherman/internal/PrecipitationSampler.java
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+/**
+ * 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.bigtop.datagenerators.weatherman.internal;
+
+import org.apache.bigtop.datagenerators.samplers.SeedFactory;
+import org.apache.bigtop.datagenerators.samplers.samplers.ConditionalSampler;
+import org.apache.bigtop.datagenerators.samplers.samplers.ExponentialSampler;
+import org.apache.bigtop.datagenerators.samplers.samplers.Sampler;
+
+public class PrecipitationSampler implements
+        ConditionalSampler<WeatherRecordBuilder, WeatherRecordBuilder> {
+  private final Sampler<Double> precipitationSampler;
+
+  public PrecipitationSampler(double averagePrecipitation,
+          SeedFactory seedFactory) {
+    precipitationSampler = new ExponentialSampler(1.0 / averagePrecipitation,
+            seedFactory);
+  }
+
+  public WeatherRecordBuilder sample(WeatherRecordBuilder record)
+          throws Exception {
+    double temp = record.getTemperature();
+    double precipitation = precipitationSampler.sample();
+    record.setPrecipitation(precipitation);
+
+    double fractionRain = 1.0
+            / (1.0 + Math.exp(-WeatherConstants.PRECIPITATION_A
+                    * (temp - WeatherConstants.PRECIPITATION_B)));
+
+    double rainfall = fractionRain * precipitation;
+    double snowfall = WeatherConstants.PRECIPITATION_TO_SNOWFALL
+            * (1.0 - fractionRain) * precipitation;
+    record.setRainFall(rainfall);
+    record.setSnowFall(snowfall);
+
+    return record;
+  }
+}