contrib/src/main/java/org/apache/apex/malhar/contrib/misc/math/Quotient.java

/**
 * 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 com.datatorrent.api.DefaultInputPort;
import com.datatorrent.api.DefaultOutputPort;
import com.datatorrent.api.annotation.OperatorAnnotation;
import com.datatorrent.lib.util.BaseNumberValueOperator;

/**
 * This operator adds all the values on "numerator" and "denominator" and emits quotient at end of window.
 * <p>
 * <br>
 * <b>StateFull : Yes </b>, Sum of values is taken over application window. <br>
 * <b>Partitions : No </b>, will yield wrong results, since values are
 * accumulated over application window. <br>
 * <br>
 * <b>Ports</b>:<br>
 * <b>numerator</b>: expects V extends Number<br>
 * <b>denominator</b>: expects V extends Number<br>
 * <b>quotient</b>: emits Double<br>
 * <br>
 * <b>Properties : </b> <br>
 * <b>mult_by : </b>Multiply by value(default = 1). <br>
 * <br>
 * @displayName Quotient
 * @category Math
 * @tags division, sum, numeric
 * @since 0.3.3
 * @deprecated
 */
@Deprecated
@OperatorAnnotation(partitionable = false)
public class Quotient<V extends Number> extends BaseNumberValueOperator<V>
{
  protected double nval = 0.0;
  protected double dval = 0.0;
  int mult_by = 1;

  /**
   * Numerator values input port.
   */
  public final transient DefaultInputPort<V> numerator = new DefaultInputPort<V>()
  {
    /**
     * Adds to the numerator value
     */
    @Override
    public void process(V tuple)
    {
      nval += tuple.doubleValue();
    }
  };

  /**
   * Denominator values input port.
   */
  public final transient DefaultInputPort<V> denominator = new DefaultInputPort<V>()
  {
    /**
     * Adds to the denominator value
     */
    @Override
    public void process(V tuple)
    {
      dval += tuple.doubleValue();
    }
  };

  /**
   * Quotient output port.
   */
  public final transient DefaultOutputPort<V> quotient = new DefaultOutputPort<V>();

  public void setMult_by(int i)
  {
    mult_by = i;
  }

  /**
   * Generates tuple emits it as long as denominator is not 0. Clears internal
   * data
   */
  @Override
  public void endWindow()
  {
    if (dval == 0) {
      return;
    }
    double val = (nval / dval) * mult_by;
    quotient.emit(getValue(val));
    nval = 0.0;
    dval = 0.0;
  }
}