Class AbstractWell

    • Nested Class Summary

      Nested Classes 
      Modifier and Type Class Description
      protected static class  AbstractWell.IndexTable
      Inner class used to store the indirection index table which is fixed for a given type of WELL class of pseudo-random number generator.
    • Field Summary

      Fields 
      Modifier and Type Field Description
      protected int index
      Current index in the bytes pool.
      protected int[] v
      Bytes pool.
    • Constructor Summary

      Constructors 
      Modifier Constructor Description
      protected AbstractWell​(int k)
      Creates a new random number generator.
      protected AbstractWell​(int k, int seed)
      Creates a new random number generator using a single int seed.
      protected AbstractWell​(int k, int[] seed)
      Creates a new random number generator using an int array seed.
      protected AbstractWell​(int k, long seed)
      Creates a new random number generator using a single long seed.
    • Method Summary

      All Methods Instance Methods Abstract Methods Concrete Methods 
      Modifier and Type Method Description
      protected void clearCache()
      Clears the cache used by the default implementation of nextGaussian.
      boolean nextBoolean()
      Returns the next pseudorandom, uniformly distributed boolean value from this random number generator's sequence.
      void nextBytes​(byte[] bytes)
      Generates random bytes and places them into a user-supplied byte array.
      void nextBytes​(byte[] bytes, int start, int len)
      Generates random bytes and places them into a user-supplied byte array.
      double nextDouble()
      Returns the next pseudorandom, uniformly distributed double value between 0.0 and 1.0 from this random number generator's sequence.
      float nextFloat()
      Returns the next pseudorandom, uniformly distributed float value between 0.0 and 1.0 from this random number generator's sequence.
      double nextGaussian()
      Returns the next pseudorandom, Gaussian ("normally") distributed double value with mean 0.0 and standard deviation 1.0 from this random number generator's sequence.
      abstract int nextInt()
      Returns the next pseudorandom, uniformly distributed int value from this random number generator's sequence.
      int nextInt​(int n)
      Returns a pseudorandom, uniformly distributed int value between 0 (inclusive) and the specified value (exclusive), drawn from this random number generator's sequence.
      long nextLong()
      Returns the next pseudorandom, uniformly distributed long value from this random number generator's sequence.
      long nextLong​(long n)
      Returns a pseudorandom, uniformly distributed int value between 0 (inclusive) and the specified value (exclusive), drawn from this random number generator's sequence.
      void setSeed​(int seed)
      Sets the seed of the underlying random number generator using an int seed.
      void setSeed​(int[] seed)
      Reinitialize the generator as if just built with the given int array seed.
      void setSeed​(long seed)
      Sets the seed of the underlying random number generator using a long seed.
      String toString()
    • Field Detail

      • index

        protected int index
        Current index in the bytes pool.
      • v

        protected final int[] v
        Bytes pool.
    • Constructor Detail

      • AbstractWell

        protected AbstractWell​(int k)
        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)
      • AbstractWell

        protected AbstractWell​(int k,
                               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)
        seed - the initial seed (32 bits integer)
      • AbstractWell

        protected AbstractWell​(int k,
                               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)
        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,
                               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)
        seed - the initial seed (64 bits integer)
    • Method Detail

      • setSeed

        public void setSeed​(int[] seed)
        Reinitialize the generator as if just built with the given int array seed.

        The state of the generator is exactly the same as a new generator built with the same seed.

        Specified by:
        setSeed in interface RandomGenerator
        Parameters:
        seed - the initial seed (32 bits integers array). If null the seed of the generator will be the system time plus the system identity hash code of the instance.
      • nextInt

        public abstract int nextInt()
        Returns the next pseudorandom, uniformly distributed int value from this random number generator's sequence.

        All 232 possible int values should be produced with (approximately) equal probability.

        Returns:
        the next pseudorandom, uniformly distributed int value from this random number generator's sequence
      • nextBoolean

        public boolean nextBoolean()
        Returns the next pseudorandom, uniformly distributed boolean value from this random number generator's sequence.
        Returns:
        the next pseudorandom, uniformly distributed boolean value from this random number generator's sequence
      • nextDouble

        public double nextDouble()
        Returns the next pseudorandom, uniformly distributed double value between 0.0 and 1.0 from this random number generator's sequence.
        Returns:
        the next pseudorandom, uniformly distributed double value between 0.0 and 1.0 from this random number generator's sequence
      • nextFloat

        public float nextFloat()
        Returns the next pseudorandom, uniformly distributed float value between 0.0 and 1.0 from this random number generator's sequence.
        Returns:
        the next pseudorandom, uniformly distributed float value between 0.0 and 1.0 from this random number generator's sequence
      • nextLong

        public long nextLong()
        Returns the next pseudorandom, uniformly distributed long value from this random number generator's sequence. All 264 possible long values should be produced with (approximately) equal probability.
        Returns:
        the next pseudorandom, uniformly distributed long value from this random number generator's sequence
      • nextBytes

        public void nextBytes​(byte[] bytes)
        Generates random bytes and places them into a user-supplied byte array. The number of random bytes produced is equal to the length of the byte array.
        Parameters:
        bytes - the non-null byte array in which to put the random bytes
      • nextBytes

        public void nextBytes​(byte[] bytes,
                              int start,
                              int len)
        Generates random bytes and places them into a user-supplied byte array.
        Parameters:
        bytes - the non-null byte array in which to put the random bytes
        start - the starting index for inserting the generated bytes into the array
        len - the number of bytes to generate
      • setSeed

        public void setSeed​(int seed)
        Sets the seed of the underlying random number generator using an int seed.

        Sequences of values generated starting with the same seeds should be identical.

        Specified by:
        setSeed in interface RandomGenerator
        Parameters:
        seed - the seed value
      • setSeed

        public void setSeed​(long seed)
        Sets the seed of the underlying random number generator using a long seed.

        Sequences of values generated starting with the same seeds should be identical.

        Specified by:
        setSeed in interface RandomGenerator
        Parameters:
        seed - the seed value
      • nextInt

        public int nextInt​(int n)
                    throws IllegalArgumentException
        Returns a pseudorandom, uniformly distributed int value between 0 (inclusive) and the specified value (exclusive), drawn from this random number generator's sequence.
        Specified by:
        nextInt in interface RandomGenerator
        Parameters:
        n - the bound on the random number to be returned. Must be positive.
        Returns:
        a pseudorandom, uniformly distributed int value between 0 (inclusive) and n (exclusive).
        Throws:
        IllegalArgumentException - if n is not positive.
      • nextLong

        public long nextLong​(long n)
        Returns a pseudorandom, uniformly distributed int value between 0 (inclusive) and the specified value (exclusive), drawn from this random number generator's sequence.
        Specified by:
        nextLong in interface RandomGenerator
        Parameters:
        n - the bound on the random number to be returned. Must be positive.
        Returns:
        a pseudorandom, uniformly distributed int value between 0 (inclusive) and n (exclusive).
      • nextGaussian

        public double nextGaussian()
        Returns the next pseudorandom, Gaussian ("normally") distributed double value with mean 0.0 and standard deviation 1.0 from this random number generator's sequence.
        Specified by:
        nextGaussian in interface RandomGenerator
        Returns:
        the next pseudorandom, Gaussian ("normally") distributed double value with mean 0.0 and standard deviation 1.0 from this random number generator's sequence
      • clearCache

        protected void clearCache()
        Clears the cache used by the default implementation of nextGaussian.