Class Product

java.lang.Object
org.apache.commons.statistics.descriptive.Product
All Implemented Interfaces:
DoubleConsumer, DoubleSupplier, IntSupplier, LongSupplier, DoubleStatistic, StatisticAccumulator<Product>, StatisticResult
public final class Product extends Object implements DoubleStatistic, StatisticAccumulator<Product>
Returns the product of the available values.
  • The result is one if no values are observed.
  • The result is NaN if any of the values is NaN.

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

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    private double
    productValue
    Product of all values.

  • Constructor Summary

    Constructors
    Modifier
    Constructor
    Description
    private
    Product()
    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.
    Product
    combine(Product other)
    Combines the state of the other statistic into this one.
    static Product
    create()
    Creates an instance.
    (package private) static Product
    createFromRange(double[] values, int from, int to)
    Create an instance using the specified range of values.
    (package private) static Product
    createFromRange(int[] values, int from, int to)
    Create an instance using the specified range of values.
    (package private) static Product
    createFromRange(long[] values, int from, int to)
    Create an instance using the specified range of values.
    double
    getAsDouble()
    Gets the product of all input values.
    static Product
    of(double... values)
    Returns an instance populated using the input values.
    static Product
    of(int... values)
    Returns an instance populated using the input values.
    static Product
    of(long... values)
    Returns an instance populated using the input values.
    static Product
    ofRange(double[] values, int from, int to)
    Returns an instance populated using the specified range of values.
    static Product
    ofRange(int[] values, int from, int to)
    Returns an instance populated using the specified range of values.
    static Product
    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

    • productValue

      private double productValue
      Product of all values.

  • Constructor Details

    • Product

      private Product()
      Create an instance.

  • Method Details

    • create

      public static Product create()
      Creates an instance.

      The initial result is one.

      Returns:
      Product instance.

    • of

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

      The result is NaN if any of the values is NaN or the product at any point is a NaN.

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

      Parameters:
      values - Values.
      Returns:
      Product instance.

    • ofRange

      public static Product 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 the product at any point is a NaN.

      When the range is empty, the result is one.

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

    • createFromRange

      static Product 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:
      Product instance.

    • of

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

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

      Parameters:
      values - Values.
      Returns:
      Product instance.

    • ofRange

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

      When the range is empty, the result is one.

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

    • createFromRange

      static Product 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:
      Product instance.

    • of

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

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

      Parameters:
      values - Values.
      Returns:
      Product instance.

    • ofRange

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

      When the range is empty, the result is one.

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

    • createFromRange

      static Product 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:
      Product 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 product of all input values.

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

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

    • combine

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