Class Skewness

  • All Implemented Interfaces:
    java.io.Serializable, StorelessUnivariateStatistic, UnivariateStatistic, MathArrays.Function

    public class Skewness
    extends AbstractStorelessUnivariateStatistic
    implements java.io.Serializable
    Computes the skewness of the available values.

    We use the following (unbiased) formula to define skewness:

    skewness = [n / (n -1) (n - 2)] sum[(x_i - mean)^3] / std^3

    where n is the number of values, mean is the Mean and std is the StandardDeviation

    Note that this statistic is undefined for n < 3. Double.Nan is returned when there is not sufficient data to compute the statistic. Double.NaN may also be returned if the input includes NaN and / or infinite values.

    Note that this implementation is not synchronized. If multiple threads access an instance of this class concurrently, and at least one of the threads invokes the increment() or clear() method, it must be synchronized externally.

    See Also:
    Serialized Form