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 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.

    • 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.

    • 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.

    • 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.