Class SumOfLogs

java.lang.Object
org.apache.commons.statistics.descriptive.SumOfLogs
All Implemented Interfaces:
DoubleConsumer, DoubleSupplier, IntSupplier, LongSupplier, DoubleStatistic, StatisticAccumulator<SumOfLogs>, StatisticResult
public final class SumOfLogs extends Object implements DoubleStatistic, StatisticAccumulator<SumOfLogs>
Returns the sum of the natural logarithm of available values.
  • The result is zero if no values are added.
  • The result is NaN if any of the values is NaN.
  • The result is NaN if any of the values is negative.

The sum follows the IEEE754 result for summing infinite values:

  • The result is +infinity if all values are in the range (0, +infinity] and at least one value is +infinity.
  • The result is -infinity if all values are in the range [0, +infinity) and at least one value is zero.
  • The result is NaN if all values are in the range [0, +infinity] and at least one value is zero, and one value is +infinity.

This class is designed to work with (though does not require) streams.

This instance is not thread safe. If multiple threads access an instance of this class concurrently, and at least one of the threads invokes the accept or combine method, it must be synchronized externally.

However, it is safe to use accept and combine as accumulator and combiner functions of Collector on a parallel stream, because the parallel instance of Stream.collect() provides the necessary partitioning, isolation, and merging of results for safe and efficient parallel execution.

Since:
1.1
See Also:

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    private final org.apache.commons.numbers.core.Sum
    delegate
    Sum used to compute the sum.

  • Constructor Summary

    Constructors
    Modifier
    Constructor
    Description
    private
    SumOfLogs()
    Create an instance.

  • Method Summary

    Modifier and Type
    Method
    Description
    void
    accept(double value)
    Updates the state of the statistic to reflect the addition of value.
    SumOfLogs
    combine(SumOfLogs other)
    Combines the state of the other statistic into this one.
    static SumOfLogs
    create()
    Creates an instance.
    (package private) static SumOfLogs
    createFromRange(double[] values, int from, int to)
    Create an instance using the specified range of values.
    (package private) static SumOfLogs
    createFromRange(int[] values, int from, int to)
    Create an instance using the specified range of values.
    (package private) static SumOfLogs
    createFromRange(long[] values, int from, int to)
    Create an instance using the specified range of values.
    double
    getAsDouble()
    Gets the sum of all input values.
    static SumOfLogs
    of(double... values)
    Returns an instance populated using the input values.
    static SumOfLogs
    of(int... values)
    Returns an instance populated using the input values.
    static SumOfLogs
    of(long... values)
    Returns an instance populated using the input values.
    static SumOfLogs
    ofRange(double[] values, int from, int to)
    Returns an instance populated using the specified range of values.
    static SumOfLogs
    ofRange(int[] values, int from, int to)
    Returns an instance populated using the specified range of values.
    static SumOfLogs
    ofRange(long[] values, int from, int to)
    Returns an instance populated using the specified range of values.

    Methods inherited from class Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

    Methods inherited from interface DoubleConsumer

    andThen

    Methods inherited from interface StatisticResult

    getAsBigInteger, getAsInt, getAsLong

  • Field Details

    • delegate

      private final org.apache.commons.numbers.core.Sum delegate
      Sum used to compute the sum.

  • Constructor Details

    • SumOfLogs

      private SumOfLogs()
      Create an instance.

  • Method Details

    • create

      public static SumOfLogs create()
      Creates an instance.

      The initial result is zero.

      Returns:
      SumOfLogs instance.

    • of

      public static SumOfLogs of(double... values)
      Returns an instance populated using the input values.

      The result is NaN if any of the values is NaN or negative; or the sum at any point is a NaN.

      When the input is an empty array, the result is zero.

      Parameters:
      values - Values.
      Returns:
      SumOfLogs instance.

    • ofRange

      public static SumOfLogs ofRange(double[] values, int from, int to)
      Returns an instance populated using the specified range of values.

      The result is NaN if any of the values is NaN or negative; or the sum at any point is a NaN.

      When the range is empty, the result is zero.

      Parameters:
      values - Values.
      from - Inclusive start of the range.
      to - Exclusive end of the range.
      Returns:
      SumOfLogs instance.
      Throws:
      IndexOutOfBoundsException - if the sub-range is out of bounds
      Since:
      1.2

    • createFromRange

      static SumOfLogs createFromRange(double[] values, int from, int to)
      Create an instance using the specified range of values.

      Warning: No range checks are performed.

      Parameters:
      values - Values.
      from - Inclusive start of the range.
      to - Exclusive end of the range.
      Returns:
      SumOfLogs instance.

    • of

      public static SumOfLogs of(int... values)
      Returns an instance populated using the input values.

      The result is NaN if any of the values is negative.

      When the input is an empty array, the result is zero.

      Parameters:
      values - Values.
      Returns:
      SumOfLogs instance.

    • ofRange

      public static SumOfLogs ofRange(int[] values, int from, int to)
      Returns an instance populated using the specified range of values.

      The result is NaN if any of the values is negative.

      When the range is empty, the result is zero.

      Parameters:
      values - Values.
      from - Inclusive start of the range.
      to - Exclusive end of the range.
      Returns:
      SumOfLogs instance.
      Throws:
      IndexOutOfBoundsException - if the sub-range is out of bounds
      Since:
      1.2

    • createFromRange

      static SumOfLogs createFromRange(int[] values, int from, int to)
      Create an instance using the specified range of values.

      Warning: No range checks are performed.

      Parameters:
      values - Values.
      from - Inclusive start of the range.
      to - Exclusive end of the range.
      Returns:
      SumOfLogs instance.

    • of

      public static SumOfLogs of(long... values)
      Returns an instance populated using the input values.

      The result is NaN if any of the values is negative.

      When the input is an empty array, the result is zero.

      Parameters:
      values - Values.
      Returns:
      SumOfLogs instance.

    • ofRange

      public static SumOfLogs ofRange(long[] values, int from, int to)
      Returns an instance populated using the specified range of values.

      The result is NaN if any of the values is negative.

      When the range is empty, the result is zero.

      Parameters:
      values - Values.
      from - Inclusive start of the range.
      to - Exclusive end of the range.
      Returns:
      SumOfLogs instance.
      Throws:
      IndexOutOfBoundsException - if the sub-range is out of bounds
      Since:
      1.2

    • createFromRange

      static SumOfLogs createFromRange(long[] values, int from, int to)
      Create an instance using the specified range of values.

      Warning: No range checks are performed.

      Parameters:
      values - Values.
      from - Inclusive start of the range.
      to - Exclusive end of the range.
      Returns:
      SumOfLogs instance.

    • accept

      public void accept(double value)
      Updates the state of the statistic to reflect the addition of value.
      Specified by:
      accept in interface DoubleConsumer
      Parameters:
      value - Value.

    • getAsDouble

      public double getAsDouble()
      Gets the sum of all input values.

      When no values have been added, the result is zero.

      Specified by:
      getAsDouble in interface DoubleSupplier
      Returns:
      sum of all values.

    • combine

      public SumOfLogs combine(SumOfLogs other)
      Description copied from interface: StatisticAccumulator
      Combines the state of the other statistic into this one.
      Specified by:
      combine in interface StatisticAccumulator<SumOfLogs>
      Parameters:
      other - Another statistic to be combined.
      Returns:
      this instance after combining other.