Package it.unimi.dsi.util

Class SplitMix64RandomGenerator

java.lang.Object
org.apache.commons.math3.random.AbstractRandomGenerator
it.unimi.dsi.util.SplitMix64RandomGenerator
All Implemented Interfaces:
Serializable, org.apache.commons.math3.random.RandomGenerator
public class SplitMix64RandomGenerator
extends org.apache.commons.math3.random.AbstractRandomGenerator
implements Serializable
A fast, high-quality, non-splittable version of the SplitMix pseudorandom number generator used by SplittableRandom. Due to the fixed increment constant and to different strategies in generating finite ranges, the methods of this generator are usually faster than those of SplittableRandom.

Note that this generator has a relatively short period (264) so it should not be used to generate very long sequences (the rule of thumb to have a period greater than the square of the length of the sequence you want to generate).

See Also:
it.unimi.dsi.util, RandomGenerator, SplitMix64Random, Serialized Form

  • Constructor Details

  • Method Details

    • nextLong

      public long nextLong()
      Specified by:
      nextLong in interface org.apache.commons.math3.random.RandomGenerator
      Overrides:
      nextLong in class org.apache.commons.math3.random.AbstractRandomGenerator

    • nextInt

      public int nextInt()
      Specified by:
      nextInt in interface org.apache.commons.math3.random.RandomGenerator
      Overrides:
      nextInt in class org.apache.commons.math3.random.AbstractRandomGenerator

    • nextInt

      public int nextInt​(int n)
      Specified by:
      nextInt in interface org.apache.commons.math3.random.RandomGenerator
      Overrides:
      nextInt in class org.apache.commons.math3.random.AbstractRandomGenerator

    • nextLong

      public long nextLong​(long n)
      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()
      Specified by:
      nextDouble in interface org.apache.commons.math3.random.RandomGenerator
      Specified by:
      nextDouble in class org.apache.commons.math3.random.AbstractRandomGenerator

    • nextFloat

      public float nextFloat()
      Specified by:
      nextFloat in interface org.apache.commons.math3.random.RandomGenerator
      Overrides:
      nextFloat in class org.apache.commons.math3.random.AbstractRandomGenerator

    • nextBoolean

      public boolean nextBoolean()
      Specified by:
      nextBoolean in interface org.apache.commons.math3.random.RandomGenerator
      Overrides:
      nextBoolean in class org.apache.commons.math3.random.AbstractRandomGenerator

    • nextBytes

      public void nextBytes​(byte[] bytes)
      Specified by:
      nextBytes in interface org.apache.commons.math3.random.RandomGenerator
      Overrides:
      nextBytes in class org.apache.commons.math3.random.AbstractRandomGenerator

    • setSeed

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

      The seed will be passed through HashCommon.murmurHash3(long).

      Specified by:
      setSeed in interface org.apache.commons.math3.random.RandomGenerator
      Specified by:
      setSeed in class org.apache.commons.math3.random.AbstractRandomGenerator
      Parameters:
      seed - a seed for this generator.

    • setState

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

    • main

      public static void main​(String[] arg)