Package org.apache.commons.math4.stat.descriptive

Interface StorelessUnivariateStatistic

All Superinterfaces:
MathArrays.Function, UnivariateStatistic
All Known Implementing Classes:
AbstractStorelessUnivariateStatistic, GeometricMean, Kurtosis, Max, Mean, Min, Product, PSquarePercentile, SecondMoment, Skewness, StandardDeviation, Sum, SumOfLogs, SumOfSquares, Variance
public interface StorelessUnivariateStatistic
extends UnivariateStatistic
Extends the definition of UnivariateStatistic with increment(double) and incrementAll(double[]) methods for adding values and updating internal state.

This interface is designed to be used for calculating statistics that can be computed in one pass through the data without storing the full array of sample values.

Note: unless otherwise stated, the UnivariateStatistic.evaluate(double[]) and UnivariateStatistic.evaluate(double[], int, int) methods do NOT alter the internal state of the respective statistic.

  • Method Summary

    Modifier and Type Method Description
    void clear()
    Clears the internal state of the Statistic
    StorelessUnivariateStatistic copy()
    Returns a copy of the statistic with the same internal state.
    long getN()
    Returns the number of values that have been added.
    double getResult()
    Returns the current value of the Statistic.
    void increment​(double d)
    Updates the internal state of the statistic to reflect the addition of the new value.
    void incrementAll​(double[] values)
    Updates the internal state of the statistic to reflect addition of all values in the values array.
    void incrementAll​(double[] values, int start, int length)
    Updates the internal state of the statistic to reflect addition of the values in the designated portion of the values array.

    Methods inherited from interface org.apache.commons.math4.stat.descriptive.UnivariateStatistic

    evaluate, evaluate

  • Method Details

    • increment

      void increment​(double d)
      Updates the internal state of the statistic to reflect the addition of the new value.
      Parameters:
      d - the new value.

    • incrementAll

      void incrementAll​(double[] values) throws MathIllegalArgumentException
      Updates the internal state of the statistic to reflect addition of all values in the values array. Does not clear the statistic first -- i.e., the values are added incrementally to the dataset.
      Parameters:
      values - array holding the new values to add
      Throws:
      MathIllegalArgumentException - if the array is null

    • incrementAll

      void incrementAll​(double[] values, int start, int length) throws MathIllegalArgumentException
      Updates the internal state of the statistic to reflect addition of the values in the designated portion of the values array. Does not clear the statistic first -- i.e., the values are added incrementally to the dataset.
      Parameters:
      values - array holding the new values to add
      start - the array index of the first value to add
      length - the number of elements to add
      Throws:
      MathIllegalArgumentException - if the array is null or the index

    • getResult

      double getResult()
      Returns the current value of the Statistic.
      Returns:
      value of the statistic, Double.NaN if it has been cleared or just instantiated.

    • getN

      long getN()
      Returns the number of values that have been added.
      Returns:
      the number of values.

    • clear

      void clear()
      Clears the internal state of the Statistic

    • copy

      StorelessUnivariateStatistic copy()
      Returns a copy of the statistic with the same internal state.
      Specified by:
      copy in interface UnivariateStatistic
      Returns:
      a copy of the statistic