| /* |
| * Copyright (c) 2013 DataTorrent, Inc. ALL Rights Reserved. |
| * |
| * Licensed 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 com.datatorrent.lib.math; |
| |
| import java.util.HashMap; |
| import java.util.Map; |
| |
| import org.apache.commons.lang.mutable.MutableDouble; |
| import org.apache.commons.lang.mutable.MutableLong; |
| |
| import com.datatorrent.api.DefaultInputPort; |
| import com.datatorrent.api.DefaultOutputPort; |
| import com.datatorrent.lib.util.BaseNumberKeyValueOperator; |
| |
| /** |
| * |
| * Emits the average value for each key at the end of window. |
| * <p> |
| * This is an end window operator. This can not be partitioned. Partitioning |
| * this will yield incorrect result.<br> |
| * <br> |
| * <b>Ports</b>:<br> |
| * <b>data</b>: expects HashMap<K,V extends Number><br> |
| * <b>average</b>: emits HashMap<K,V extends Number></b><br> |
| * <br> |
| * <br> |
| * <b>Properties</b>:<br> |
| * <b>inverse</b>: if set to true the key in the filter will block tuple<br> |
| * <b>filterBy</b>: List of keys to filter on<br> |
| * <br> |
| * <b>Specific compile time checks</b>: None<br> |
| * <b>Specific run time checks</b>: None<br> |
| * <p> |
| * <br> |
| * @displayName Average Map |
| * @category Math |
| * @tags average, numeric, end window, key value, aggregate |
| * @since 0.3.3 |
| */ |
| public class AverageMap<K, V extends Number> extends |
| BaseNumberKeyValueOperator<K, V> |
| { |
| |
| // Aggregate values in hash map. |
| protected HashMap<K, MutableDouble> sums = new HashMap<K, MutableDouble>(); |
| protected HashMap<K, MutableLong> counts = new HashMap<K, MutableLong>(); |
| |
| /** |
| * Input data port that takes a map of <key,value>. |
| */ |
| public final transient DefaultInputPort<Map<K, V>> data = new DefaultInputPort<Map<K, V>>() |
| { |
| /** |
| * For each tuple (a HashMap of key,val pairs) adds the values for each key, |
| * counts the number of occurrences of each key and computes the average. |
| */ |
| @Override |
| public void process(Map<K, V> tuple) |
| { |
| for (Map.Entry<K, V> e : tuple.entrySet()) { |
| K key = e.getKey(); |
| if (!doprocessKey(key)) { |
| continue; |
| } |
| |
| MutableDouble val = sums.get(key); |
| if (val == null) { |
| val = new MutableDouble(e.getValue().doubleValue()); |
| } else { |
| val.add(e.getValue().doubleValue()); |
| } |
| sums.put(cloneKey(key), val); |
| |
| MutableLong count = counts.get(key); |
| if (count == null) { |
| count = new MutableLong(0); |
| counts.put(cloneKey(key), count); |
| } |
| count.increment(); |
| } |
| } |
| }; |
| |
| /** |
| * Average output port that emits a hashmap. |
| */ |
| public final transient DefaultOutputPort<HashMap<K, V>> average = new DefaultOutputPort<HashMap<K, V>>() |
| { |
| }; |
| |
| /** |
| * Emits average for each key in end window. Data is precomputed during |
| * process on input port Clears the internal data before return. |
| */ |
| @Override |
| public void endWindow() |
| { |
| HashMap<K, V> atuples = new HashMap<K, V>(); |
| for (Map.Entry<K, MutableDouble> e : sums.entrySet()) { |
| K key = e.getKey(); |
| atuples.put(key, getValue(e.getValue().doubleValue() |
| / counts.get(key).doubleValue())); |
| } |
| |
| if (!atuples.isEmpty()) { |
| average.emit(atuples); |
| } |
| sums.clear(); |
| counts.clear(); |
| } |
| } |