How to use org.apache.commons.math.stat.descriptive.moment

/**
 * Copies source to dest.
 * <p>Neither source nor dest can be null.</p>
 *
 * @param source StandardDeviation to copy
 * @param dest StandardDeviation to copy to
 * @throws NullPointerException if either source or dest is null
 */
public static void copy(StandardDeviation source, StandardDeviation dest) {
  dest.setData(source.getDataRef());
  dest.variance = source.variance.copy();
}

/**
 * Copies source to dest.
 * <p>Neither source nor dest can be null.</p>
 *
 * @param source Kurtosis to copy
 * @param dest Kurtosis to copy to
 * @throws NullPointerException if either source or dest is null
 */
public static void copy(Kurtosis source, Kurtosis dest) {
  dest.setData(source.getDataRef());
  dest.moment = source.moment.copy();
  dest.incMoment = source.incMoment;
}

  /**
   * Copies source to dest.
   * <p>Neither source nor dest can be null.</p>
   *
   * @param source Skewness to copy
   * @param dest Skewness to copy to
   * @throws NullPointerException if either source or dest is null
   */
  public static void copy(Skewness source, Skewness dest) {
    dest.setData(source.getDataRef());
    dest.moment = new ThirdMoment(source.moment.copy());
    dest.incMoment = source.incMoment;
  }
}

/** Constructs a VectorialMean.
 * @param dimension vectors dimension
 */
public VectorialMean(int dimension) {
  means = new Mean[dimension];
  for (int i = 0; i < dimension; ++i) {
    means[i] = new Mean();
  }
}

/**
 * {@inheritDoc}
 */
@Override
public StandardDeviation copy() {
  StandardDeviation result = new StandardDeviation();
  copy(this, result);
  return result;
}

/**
 * {@inheritDoc}
 */
@Override
public Variance copy() {
  Variance result = new Variance();
  copy(this, result);
  return result;
}

/**
 * {@inheritDoc}
 */
@Override
public ThirdMoment copy() {
  ThirdMoment result = new ThirdMoment();
  copy(this, result);
  return result;
}

/**
 * Constructs a Variance with default (true) <code>isBiasCorrected</code>
 * property.
 */
public Variance() {
  moment = new SecondMoment();
}

  /**
   * Copies source to dest.
   * <p>Neither source nor dest can be null.</p>
   *
   * @param source Mean to copy
   * @param dest Mean to copy to
   * @throws NullPointerException if either source or dest is null
   */
  public static void copy(Mean source, Mean dest) {
    dest.setData(source.getDataRef());
    dest.incMoment = source.incMoment;
    dest.moment = source.moment.copy();
  }
}

/**
 * {@inheritDoc}
 */
@Override
public void clear() {
  if (incMoment) {
    moment.clear();
  }
}

/**
 * @return Returns the isBiasCorrected.
 */
public boolean isBiasCorrected() {
  return variance.isBiasCorrected();
}

/**
 * {@inheritDoc}
 */
@Override
public void clear() {
  if (incMoment) {
    moment.clear();
  }
}

/**
 * {@inheritDoc}
 */
@Override
public void increment(final double d) {
  if (incMoment) {
    moment.increment(d);
  }
}

/**
 * {@inheritDoc}
 */
@Override
public void increment(final double d) {
  if (incMoment) {
    moment.increment(d);
  }
}

/**
 * Copy constructor, creates a new {@code Mean} identical
 * to the {@code original}
 *
 * @param original the {@code Mean} instance to copy
 */
public Mean(Mean original) {
  copy(original, this);
}

/**
 * Copy constructor, creates a new {@code Skewness} identical
 * to the {@code original}
 *
 * @param original the {@code Skewness} instance to copy
 */
public Skewness(Skewness original) {
  copy(original, this);
}

/**
 * Copy constructor, creates a new {@code FourthMoment} identical
 * to the {@code original}
 *
 * @param original the {@code FourthMoment} instance to copy
 */
 public FourthMoment(FourthMoment original) {
   super();
   copy(original, this);
 }

/**
 * Copy constructor, creates a new {@code Variance} identical
 * to the {@code original}
 *
 * @param original the {@code Variance} instance to copy
 */
public Variance(Variance original) {
  copy(original, this);
}

/**
 * Copies source to dest.
 * <p>Neither source nor dest can be null.</p>
 *
 * @param source SecondMoment to copy
 * @param dest SecondMoment to copy to
 * @throws NullPointerException if either source or dest is null
 */
public static void copy(SecondMoment source, SecondMoment dest) {
  FirstMoment.copy(source, dest);
  dest.m2 = source.m2;
}

/**
 * {@inheritDoc}
 */
@Override
public void clear() {
  super.clear();
  m2 = Double.NaN;
}