content: /**
   * 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.contrib.misc.math;
  
  import org.apache.apex.malhar.lib.util.BaseNumberValueOperator;
  
  import com.datatorrent.api.DefaultInputPort;
  import com.datatorrent.api.DefaultOutputPort;
  import com.datatorrent.api.annotation.OutputPortFieldAnnotation;
  
  /**
   * 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.&nbsp;
   * This emits &lt;change in value,percentage change&gt;.
   * 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
   * @deprecated
   */
  @Deprecated
  public class Change<V extends Number> extends BaseNumberValueOperator<V>
  {
          /**
     * Input data port that takes a number.
     */
    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&nbsp; It stores the value for base comparison.
     */
    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(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(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;
  }
  