| /** |
| * 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 com.datatorrent.lib.math; |
| |
| import com.datatorrent.api.DefaultInputPort; |
| import com.datatorrent.api.DefaultOutputPort; |
| import com.datatorrent.api.annotation.OperatorAnnotation; |
| import com.datatorrent.common.util.BaseOperator; |
| |
| /** |
| * Calculate the running average of the input numbers and emit it at the end of the window. |
| * <p> |
| * This is an end of window operator.<br> |
| * <br> |
| * <b>StateFull : Yes</b>, average is computed over application window. <br> |
| * <b>Partitions : No</b>, will yield wrong results. <br> |
| * <br> |
| * <b>Ports</b>:<br> |
| * <b>input</b>: expects Number<br> |
| * <b>longAverage</b>: emits Long<br> |
| * <b>integerAverage</b>: emits Integer<br> |
| * <b>doubleAverage</b>: emits Double<br> |
| * <b>floatAverage</b>: emits Float<br> |
| * <br> |
| * @displayName Running Average |
| * @category Math |
| * @tags average, numeric |
| * @since 0.3.3 |
| */ |
| @OperatorAnnotation(partitionable = false) |
| public class RunningAverage extends BaseOperator |
| { |
| /** |
| * Computed average. |
| */ |
| double average; |
| |
| /** |
| * Number of values on input port. |
| */ |
| long count; |
| |
| /** |
| * Input number port. |
| */ |
| public final transient DefaultInputPort<Number> input = new DefaultInputPort<Number>() |
| { |
| @Override |
| public void process(Number tuple) |
| { |
| // Floating mean as explained on http://www.heikohoffmann.de/htmlthesis/node134.html |
| double firstPart = (1.0 / (++RunningAverage.this.count)); |
| double secondPart = (tuple.doubleValue() - average); |
| average += (firstPart * secondPart); |
| } |
| }; |
| |
| /** |
| * Double average output port. |
| */ |
| public final transient DefaultOutputPort<Double> doubleAverage = new DefaultOutputPort<Double>(); |
| |
| /** |
| * Float average output port. |
| */ |
| public final transient DefaultOutputPort<Float> floatAverage = new DefaultOutputPort<Float>(); |
| |
| /** |
| * Long average output port. |
| */ |
| public final transient DefaultOutputPort<Long> longAverage = new DefaultOutputPort<Long>(); |
| |
| /** |
| * Integer average output port. |
| */ |
| public final transient DefaultOutputPort<Integer> integerAverage = new DefaultOutputPort<Integer>(); |
| |
| /** |
| * End window operator override. |
| */ |
| @Override |
| public void endWindow() |
| { |
| if (doubleAverage.isConnected()) { |
| doubleAverage.emit(average); |
| } |
| |
| if (floatAverage.isConnected()) { |
| floatAverage.emit((float)average); |
| } |
| |
| if (longAverage.isConnected()) { |
| longAverage.emit((long)average); |
| } |
| |
| if (integerAverage.isConnected()) { |
| integerAverage.emit((int)average); |
| } |
| } |
| } |