| /** |
| * 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.apex.malhar.lib.window.accumulation; |
| |
| import org.apache.apex.malhar.lib.window.Accumulation; |
| import org.apache.commons.lang3.tuple.MutablePair; |
| |
| /** |
| * Average Accumulation |
| * |
| * @since 3.5.0 |
| */ |
| public class Average implements Accumulation<Double, MutablePair<Double, Long>, Double> |
| { |
| @Override |
| public MutablePair<Double, Long> defaultAccumulatedValue() |
| { |
| return new MutablePair<>(0.0, 0L); |
| } |
| |
| @Override |
| public MutablePair<Double, Long> accumulate(MutablePair<Double, Long> accu, Double input) |
| { |
| accu.setLeft(accu.getLeft() * ((double)accu.getRight() / (accu.getRight() + 1)) + input / (accu.getRight() + 1)); |
| accu.setRight(accu.getRight() + 1); |
| return accu; |
| } |
| |
| @Override |
| public MutablePair<Double, Long> merge(MutablePair<Double, Long> accu1, MutablePair<Double, Long> accu2) |
| { |
| accu1.setLeft(accu1.getLeft() * ((double)accu1.getRight() / accu1.getRight() + accu2.getRight()) + |
| accu2.getLeft() * ((double)accu2.getRight() / accu1.getRight() + accu2.getRight())); |
| accu1.setRight(accu1.getRight() + accu2.getRight()); |
| return accu1; |
| } |
| |
| @Override |
| public Double getOutput(MutablePair<Double, Long> accumulatedValue) |
| { |
| return accumulatedValue.getLeft(); |
| } |
| |
| @Override |
| public Double getRetraction(Double value) |
| { |
| // TODO: Need to add implementation for retraction. |
| return 0.0; |
| } |
| } |