Class XorShift64StarRandom

  • All Implemented Interfaces:
    java.io.Serializable

    @Deprecated
    public class XorShift64StarRandom
    extends java.util.Random
    Deprecated.
    Use SplitMix64Random instead.
    A fast, good-quality pseudorandom number generator that combines George Marsaglia's Xorshift generators (described in “Xorshift RNGs”, Journal of Statistical Software, 8:1−6, 2003) with a multiplication.
    See Also:
    Serialized Form
    • Method Summary

      All Methods Instance Methods Concrete Methods Deprecated Methods 
      Modifier and Type Method Description
      protected int next​(int bits)
      Deprecated.
       
      boolean nextBoolean()
      Deprecated.
       
      void nextBytes​(byte[] bytes)
      Deprecated.
       
      double nextDouble()
      Deprecated.
       
      float nextFloat()
      Deprecated.
       
      int nextInt()
      Deprecated.
       
      int nextInt​(int n)
      Deprecated.
      Returns a pseudorandom, approximately uniformly distributed int value between 0 (inclusive) and the specified value (exclusive), drawn from this random number generator's sequence.
      long nextLong()
      Deprecated.
       
      long nextLong​(long n)
      Deprecated.
      Returns a pseudorandom uniformly distributed long value between 0 (inclusive) and the specified value (exclusive), drawn from this random number generator's sequence.
      void setSeed​(long seed)
      Deprecated.
      Sets the seed of this generator.
      void setState​(long state)
      Deprecated.
      Sets the state of this generator.
      • Methods inherited from class java.util.Random

        doubles, doubles, doubles, doubles, ints, ints, ints, ints, longs, longs, longs, longs, nextGaussian
      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
    • Constructor Detail

      • XorShift64StarRandom

        public XorShift64StarRandom()
        Deprecated.
        Creates a new generator seeded using Util.randomSeed().
      • XorShift64StarRandom

        public XorShift64StarRandom​(long seed)
        Deprecated.
        Creates a new generator using a given seed.
        Parameters:
        seed - a nonzero seed for the generator (if zero, the generator will be seeded with Long.MIN_VALUE).
    • Method Detail

      • next

        protected int next​(int bits)
        Deprecated.
        Overrides:
        next in class java.util.Random
      • nextLong

        public long nextLong()
        Deprecated.
        Overrides:
        nextLong in class java.util.Random
      • nextInt

        public int nextInt()
        Deprecated.
        Overrides:
        nextInt in class java.util.Random
      • nextInt

        public int nextInt​(int n)
        Deprecated.
        Returns a pseudorandom, approximately uniformly distributed int value between 0 (inclusive) and the specified value (exclusive), drawn from this random number generator's sequence.

        The hedge “approximately” is due to the fact that to be always faster than ThreadLocalRandom we return the upper 63 bits of nextLong() modulo n instead of using Random's fancy algorithm (which nextLong(long) uses though). This choice introduces a bias: the numbers from 0 to 263 mod n are slightly more likely than the other ones. In the worst case, “more likely” means 1.00000000023 times more likely, which is in practice undetectable (actually, due to the abysmally low quality of Random's generator, the result is statistically better in any case than Random.nextInt(int)'s) .

        If for some reason you need truly uniform generation, just use nextLong(long).

        Overrides:
        nextInt in class java.util.Random
        Parameters:
        n - the positive bound on the random number to be returned.
        Returns:
        the next pseudorandom int value between 0 (inclusive) and n (exclusive).
      • nextLong

        public long nextLong​(long n)
        Deprecated.
        Returns a pseudorandom uniformly distributed long value between 0 (inclusive) and the specified value (exclusive), drawn from this random number generator's sequence. The algorithm used to generate the value guarantees that the result is uniform, provided that the sequence of 64-bit values produced by this generator is.
        Parameters:
        n - the positive bound on the random number to be returned.
        Returns:
        the next pseudorandom long value between 0 (inclusive) and n (exclusive).
      • nextDouble

        public double nextDouble()
        Deprecated.
        Overrides:
        nextDouble in class java.util.Random
      • nextFloat

        public float nextFloat()
        Deprecated.
        Overrides:
        nextFloat in class java.util.Random
      • nextBoolean

        public boolean nextBoolean()
        Deprecated.
        Overrides:
        nextBoolean in class java.util.Random
      • nextBytes

        public void nextBytes​(byte[] bytes)
        Deprecated.
        Overrides:
        nextBytes in class java.util.Random
      • setSeed

        public void setSeed​(long seed)
        Deprecated.
        Sets the seed of this generator.

        The seed will be passed through HashCommon.murmurHash3(long). In this way, if the user passes a small value we will avoid the short irregular transient associated with states with a very small number of bits set.

        Overrides:
        setSeed in class java.util.Random
        Parameters:
        seed - a nonzero seed for this generator (if zero, the generator will be seeded with Long.MIN_VALUE).
      • setState

        public void setState​(long state)
        Deprecated.
        Sets the state of this generator.
        Parameters:
        state - the new state for this generator (must be nonzero).