| /* |
| * 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 com.datatorrent.api.DefaultInputPort; |
| import com.datatorrent.api.DefaultOutputPort; |
| import com.datatorrent.api.annotation.InputPortFieldAnnotation; |
| import com.datatorrent.api.annotation.OutputPortFieldAnnotation; |
| import com.datatorrent.lib.util.BaseNumberValueOperator; |
| |
| /** |
| * Operator compares data values arriving on input port with base value input operator. |
| * |
| * <p> |
| * Arriving base value is stored in operator for comparison, old base value is overwritten. |
| * This emits <change in value,percentage change>. |
| * Operator expects values arriving on data input port and base value input operator. |
| * Change in value and percentage change in values are emitted on separate ports.<br> |
| * This operator can not be partitioned, since copies won't get consecutive operators. <br> |
| * This is StateFull operator, tuples that arrive on base port are kept in |
| * cache forever.<br> |
| * <br> |
| * <b>Input Ports</b>:<br> |
| * <b>data</b>: expects V extends Number, Data values<br> |
| * <b>base</b>: expects V extends Number, Base Value stored for comparison<br> |
| * |
| * <b>Output Ports</b>:<br> |
| * <b>change</b>: emits V extends Number, Diff from base value<br> |
| * <b>percent</b>: emits Doubl, percent change in value compared to base value.<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> |
| * <br> |
| * |
| * <br> |
| * @displayname: Change |
| * @category: math |
| * @tags: change, key value, numeric, percentage |
| * @since 0.3.3 |
| */ |
| public class Change<V extends Number> extends BaseNumberValueOperator<V> |
| { |
| /** |
| * Input data port that takes a number. |
| */ |
| @InputPortFieldAnnotation(name = "data") |
| public final transient DefaultInputPort<V> data = new DefaultInputPort<V>() |
| { |
| /** |
| * Process each key, compute change or percent, and emit it. |
| */ |
| @Override |
| public void process(V tuple) |
| { |
| if (baseValue != 0) { // Avoid divide by zero, Emit an error tuple? |
| double cval = tuple.doubleValue() - baseValue; |
| change.emit(getValue(cval)); |
| percent.emit((cval / baseValue) * 100); |
| } |
| } |
| }; |
| |
| /** |
| * Input port that takes a number It stores the value for base comparison. |
| */ |
| @InputPortFieldAnnotation(name = "base") |
| public final transient DefaultInputPort<V> base = new DefaultInputPort<V>() |
| { |
| /** |
| * Process each key to store the value. If same key appears again update |
| * with latest value. |
| */ |
| @Override |
| public void process(V tuple) |
| { |
| if (tuple.doubleValue() != 0.0) { // Avoid divide by zero, Emit an error |
| // tuple? |
| baseValue = tuple.doubleValue(); |
| } |
| } |
| }; |
| |
| /** |
| * Output port that emits change in value compared to base value. |
| */ |
| @OutputPortFieldAnnotation(name = "change", optional = true) |
| public final transient DefaultOutputPort<V> change = new DefaultOutputPort<V>(); |
| |
| /** |
| * Output port that emits percent change in data value compared to base value. |
| */ |
| @OutputPortFieldAnnotation(name = "percent", optional = true) |
| public final transient DefaultOutputPort<Double> percent = new DefaultOutputPort<Double>(); |
| |
| /** |
| * baseValue is a state full field. It is retained across windows. |
| */ |
| private double baseValue = 0; |
| } |