Package org.apache.commons.math3.stat.descriptive

Class SynchronizedDescriptiveStatistics

java.lang.Object
org.apache.commons.math3.stat.descriptive.DescriptiveStatistics
org.apache.commons.math3.stat.descriptive.SynchronizedDescriptiveStatistics
All Implemented Interfaces:
Serializable, StatisticalSummary
public class SynchronizedDescriptiveStatistics extends DescriptiveStatistics
Implementation of DescriptiveStatistics that is safe to use in a multithreaded environment. Multiple threads can safely operate on a single instance without causing runtime exceptions due to race conditions. In effect, this implementation makes modification and access methods atomic operations for a single instance. That is to say, as one thread is computing a statistic from the instance, no other thread can modify the instance nor compute another statistic.
Since:
1.2
See Also:

  • Constructor Details

  • Method Details

    • addValue

      public void addValue(double v)
      Adds the value to the dataset. If the dataset is at the maximum size (i.e., the number of stored elements equals the currently configured windowSize), the first (oldest) element in the dataset is discarded to make room for the new value.
      Overrides:
      addValue in class DescriptiveStatistics
      Parameters:
      v - the value to be added

    • apply

      public double apply(UnivariateStatistic stat)
      Apply the given statistic to the data associated with this set of statistics.
      Overrides:
      apply in class DescriptiveStatistics
      Parameters:
      stat - the statistic to apply
      Returns:
      the computed value of the statistic.

    • clear

      public void clear()
      Resets all statistics and storage
      Overrides:
      clear in class DescriptiveStatistics

    • getElement

      public double getElement(int index)
      Returns the element at the specified index
      Overrides:
      getElement in class DescriptiveStatistics
      Parameters:
      index - The Index of the element
      Returns:
      return the element at the specified index

    • getN

      public long getN()
      Returns the number of available values
      Specified by:
      getN in interface StatisticalSummary
      Overrides:
      getN in class DescriptiveStatistics
      Returns:
      The number of available values

    • getStandardDeviation

      public double getStandardDeviation()
      Returns the standard deviation of the available values.
      Specified by:
      getStandardDeviation in interface StatisticalSummary
      Overrides:
      getStandardDeviation in class DescriptiveStatistics
      Returns:
      The standard deviation, Double.NaN if no values have been added or 0.0 for a single value set.

    • getQuadraticMean

      public double getQuadraticMean()
      Returns the quadratic mean, a.k.a. root-mean-square of the available values
      Overrides:
      getQuadraticMean in class DescriptiveStatistics
      Returns:
      The quadratic mean or Double.NaN if no values have been added.

    • getValues

      public double[] getValues()
      Returns the current set of values in an array of double primitives. The order of addition is preserved. The returned array is a fresh copy of the underlying data -- i.e., it is not a reference to the stored data.
      Overrides:
      getValues in class DescriptiveStatistics
      Returns:
      returns the current set of numbers in the order in which they were added to this set

    • getWindowSize

      public int getWindowSize()
      Returns the maximum number of values that can be stored in the dataset, or INFINITE_WINDOW (-1) if there is no limit.
      Overrides:
      getWindowSize in class DescriptiveStatistics
      Returns:
      The current window size or -1 if its Infinite.

    • setWindowSize

      public void setWindowSize(int windowSize) throws MathIllegalArgumentException
      WindowSize controls the number of values that contribute to the reported statistics. For example, if windowSize is set to 3 and the values {1,2,3,4,5} have been added in that order then the available values are {3,4,5} and all reported statistics will be based on these values. If windowSize is decreased as a result of this call and there are more than the new value of elements in the current dataset, values from the front of the array are discarded to reduce the dataset to windowSize elements.
      Overrides:
      setWindowSize in class DescriptiveStatistics
      Parameters:
      windowSize - sets the size of the window.
      Throws:
      MathIllegalArgumentException - if window size is less than 1 but not equal to DescriptiveStatistics.INFINITE_WINDOW

    • toString

      public String toString()
      Generates a text report displaying univariate statistics from values that have been added. Each statistic is displayed on a separate line.
      Overrides:
      toString in class DescriptiveStatistics
      Returns:
      String with line feeds displaying statistics

    • copy

      public SynchronizedDescriptiveStatistics copy()
      Returns a copy of this SynchronizedDescriptiveStatistics instance with the same internal state.
      Overrides:
      copy in class DescriptiveStatistics
      Returns:
      a copy of this

    • copy

      public static void copy(SynchronizedDescriptiveStatistics source, SynchronizedDescriptiveStatistics dest) throws NullArgumentException
      Copies source to dest.

      Neither source nor dest can be null.

      Acquires synchronization lock on source, then dest before copying.

      Parameters:
      source - SynchronizedDescriptiveStatistics to copy
      dest - SynchronizedDescriptiveStatistics to copy to
      Throws:
      NullArgumentException - if either source or dest is null