RunningAverager.java

package org.fluxoid.utils;

public class RunningAverager implements Averager {

  private FixedSizeFifo<Double> values;
  private Double lastValue;

  public RunningAverager(int samplesToAverage) {
    values = new FixedSizeFifo<Double>(samplesToAverage);
  }

  /* (non-Javadoc)
   * @see org.cowboycoders.location.Averager#add(double)
   */
  @Override
  public void add(double y) {
    lastValue = y;
    values.offer(y);
  }

  /* (non-Javadoc)
   * @see org.cowboycoders.location.Averager#getLastValue()
   */
  @Override
  public Double getLastValue() throws NullPointerException {
    return lastValue;
  }

  /* (non-Javadoc)
   * @see org.cowboycoders.location.Averager#getAverage()
   */
  @Override
  public double getAverage() {
    double total = 0;
    for (double value : values) {
      total += value;
    }
    return total / values.size();
  }


  public static void main(String[] args) {
    RunningAverager a = new RunningAverager(10);
    a.add(4);
    a.add(6);
    a.add(4);
    a.add(6);
    a.add(4);
    a.add(6);
    a.add(4);
    a.add(6);
    System.out.println(a.getAverage());
  }

  @Override
  public int getNumberOfSamples() {
    return values.size();
  }

}