com.datatorrent.lib.math.RunningAverage Maven / Gradle / Ivy
/**
* 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.
*
* This is an end of window operator.
*
* StateFull : Yes, average is computed over application window.
* Partitions : No, will yield wrong results.
*
* Ports:
* input: expects Number
* longAverage: emits Long
* integerAverage: emits Integer
* doubleAverage: emits Double
* floatAverage: emits Float
*
* @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 input = new DefaultInputPort()
{
@Override
public void process(Number tuple)
{
double sum = (count * average) + tuple.doubleValue();
count++;
average = sum / count;
}
};
/**
* Double average output port.
*/
public final transient DefaultOutputPort doubleAverage = new DefaultOutputPort();
/**
* Float average output port.
*/
public final transient DefaultOutputPort floatAverage = new DefaultOutputPort();
/**
* Long average output port.
*/
public final transient DefaultOutputPort longAverage = new DefaultOutputPort();
/**
* Integer average output port.
*/
public final transient DefaultOutputPort integerAverage = new DefaultOutputPort();
/**
* 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);
}
}
}