Package org.apache.commons.math3.random

Class AbstractWell

java.lang.Object
org.apache.commons.math3.random.BitsStreamGenerator
org.apache.commons.math3.random.AbstractWell
All Implemented Interfaces:
Serializable, RandomGenerator
Direct Known Subclasses:
Well1024a, Well19937a, Well19937c, Well44497a, Well44497b, Well512a
public abstract class AbstractWell extends BitsStreamGenerator implements Serializable
This abstract class implements the WELL class of pseudo-random number generator from François Panneton, Pierre L'Ecuyer and Makoto Matsumoto.

This generator is described in a paper by François Panneton, Pierre L'Ecuyer and Makoto Matsumoto Improved Long-Period Generators Based on Linear Recurrences Modulo 2 ACM Transactions on Mathematical Software, 32, 1 (2006). The errata for the paper are in wellrng-errata.txt.

Since:
2.2
See Also:

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    protected final int[]
    i1
    Index indirection table giving for each index the value index + m1 taking table size into account.
    protected final int[]
    i2
    Index indirection table giving for each index the value index + m2 taking table size into account.
    protected final int[]
    i3
    Index indirection table giving for each index the value index + m3 taking table size into account.
    protected int
    index
    Current index in the bytes pool.
    protected final int[]
    iRm1
    Index indirection table giving for each index its predecessor taking table size into account.
    protected final int[]
    iRm2
    Index indirection table giving for each index its second predecessor taking table size into account.
    protected final int[]
    v
    Bytes pool.

  • Constructor Summary

    Constructors
    Modifier
    Constructor
    Description
    protected
    AbstractWell(int k, int m1, int m2, int m3)
    Creates a new random number generator.
    protected
    AbstractWell(int k, int m1, int m2, int m3, int seed)
    Creates a new random number generator using a single int seed.
    protected
    AbstractWell(int k, int m1, int m2, int m3, int[] seed)
    Creates a new random number generator using an int array seed.
    protected
    AbstractWell(int k, int m1, int m2, int m3, long seed)
    Creates a new random number generator using a single long seed.

  • Method Summary

    Modifier and Type
    Method
    Description
    protected abstract int
    next(int bits)
    Generate next pseudorandom number.
    void
    setSeed(int seed)
    Reinitialize the generator as if just built with the given int seed.
    void
    setSeed(int[] seed)
    Reinitialize the generator as if just built with the given int array seed.
    void
    setSeed(long seed)
    Reinitialize the generator as if just built with the given long seed.

    Methods inherited from class org.apache.commons.math3.random.BitsStreamGenerator

    clear, nextBoolean, nextBytes, nextBytes, nextDouble, nextFloat, nextGaussian, nextInt, nextInt, nextLong, nextLong

    Methods inherited from class java.lang.Object

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

  • Field Details

    • index

      protected int index
      Current index in the bytes pool.

    • v

      protected final int[] v
      Bytes pool.

    • iRm1

      protected final int[] iRm1
      Index indirection table giving for each index its predecessor taking table size into account.

    • iRm2

      protected final int[] iRm2
      Index indirection table giving for each index its second predecessor taking table size into account.

    • i1

      protected final int[] i1
      Index indirection table giving for each index the value index + m1 taking table size into account.

    • i2

      protected final int[] i2
      Index indirection table giving for each index the value index + m2 taking table size into account.

    • i3

      protected final int[] i3
      Index indirection table giving for each index the value index + m3 taking table size into account.

  • Constructor Details

    • AbstractWell

      protected AbstractWell(int k, int m1, int m2, int m3)
      Creates a new random number generator.

      The instance is initialized using the current time plus the system identity hash code of this instance as the seed.

      Parameters:
      k - number of bits in the pool (not necessarily a multiple of 32)
      m1 - first parameter of the algorithm
      m2 - second parameter of the algorithm
      m3 - third parameter of the algorithm

    • AbstractWell

      protected AbstractWell(int k, int m1, int m2, int m3, int seed)
      Creates a new random number generator using a single int seed.
      Parameters:
      k - number of bits in the pool (not necessarily a multiple of 32)
      m1 - first parameter of the algorithm
      m2 - second parameter of the algorithm
      m3 - third parameter of the algorithm
      seed - the initial seed (32 bits integer)

    • AbstractWell

      protected AbstractWell(int k, int m1, int m2, int m3, int[] seed)
      Creates a new random number generator using an int array seed.
      Parameters:
      k - number of bits in the pool (not necessarily a multiple of 32)
      m1 - first parameter of the algorithm
      m2 - second parameter of the algorithm
      m3 - third parameter of the algorithm
      seed - the initial seed (32 bits integers array), if null the seed of the generator will be related to the current time

    • AbstractWell

      protected AbstractWell(int k, int m1, int m2, int m3, long seed)
      Creates a new random number generator using a single long seed.
      Parameters:
      k - number of bits in the pool (not necessarily a multiple of 32)
      m1 - first parameter of the algorithm
      m2 - second parameter of the algorithm
      m3 - third parameter of the algorithm
      seed - the initial seed (64 bits integer)

  • Method Details