Package org.apache.commons.rng.core.source64

Class XoRoShiRo128PlusPlus

java.lang.Object
org.apache.commons.rng.core.BaseProvider
org.apache.commons.rng.core.source64.LongProvider
org.apache.commons.rng.core.source64.AbstractXoRoShiRo128
org.apache.commons.rng.core.source64.XoRoShiRo128PlusPlus
All Implemented Interfaces:
RandomLongSource, JumpableUniformRandomProvider, LongJumpableUniformRandomProvider, RestorableUniformRandomProvider, UniformRandomProvider
public class XoRoShiRo128PlusPlus extends AbstractXoRoShiRo128
A fast all-purpose 64-bit generator.

This is a member of the Xor-Shift-Rotate family of generators. Memory footprint is 128 bits and the period is 2128-1. Speed is expected to be similar to XoShiRo256StarStar.

Since:
1.3
See Also:

  • Field Details

    • JUMP_COEFFICIENTS

      private static final long[] JUMP_COEFFICIENTS
      The coefficients for the jump function.

    • LONG_JUMP_COEFFICIENTS

      private static final long[] LONG_JUMP_COEFFICIENTS
      The coefficients for the long jump function.

  • Constructor Details

    • XoRoShiRo128PlusPlus

      public XoRoShiRo128PlusPlus(long[] seed)
      Creates a new instance.
      Parameters:
      seed - Initial seed. If the length is larger than 2, only the first 2 elements will be used; if smaller, the remaining elements will be automatically set. A seed containing all zeros will create a non-functional generator.

    • XoRoShiRo128PlusPlus

      public XoRoShiRo128PlusPlus(long seed0, long seed1)
      Creates a new instance using a 2 element seed. A seed containing all zeros will create a non-functional generator.
      Parameters:
      seed0 - Initial seed element 0.
      seed1 - Initial seed element 1.

    • XoRoShiRo128PlusPlus

      protected XoRoShiRo128PlusPlus(XoRoShiRo128PlusPlus source)
      Creates a copy instance.
      Parameters:
      source - Source to copy.

  • Method Details

    • next

      public long next()
      Return the next random value.
      Specified by:
      next in interface RandomLongSource
      Overrides:
      next in class AbstractXoRoShiRo128
      Returns:
      the next random value.

    • nextOutput

      protected long nextOutput()
      Use the current state to compute the next output from the generator. The output function shall vary with respect to different generators. This method is called from AbstractXoRoShiRo128.next() before the current state is updated.
      Specified by:
      nextOutput in class AbstractXoRoShiRo128
      Returns:
      the next output

    • jump

      public UniformRandomProvider jump()
      Creates a copy of the UniformRandomProvider and then advances the state of the current instance. The copy is returned.

      The current state will be advanced in a single operation by the equivalent of a number of sequential calls to a method that updates the state of the provider. The size of the jump is implementation dependent.

      Repeat invocations of this method will create a series of generators that are uniformly spaced at intervals of the output sequence. Each generator provides non-overlapping output for the length of the jump for use in parallel computations.

      The jump size is the equivalent of 264 calls to nextLong(). It can provide up to 264 non-overlapping subsequences.

      Specified by:
      jump in interface JumpableUniformRandomProvider
      Overrides:
      jump in class AbstractXoRoShiRo128
      Returns:
      A copy of the current state.

    • longJump

      public JumpableUniformRandomProvider longJump()
      Creates a copy of the JumpableUniformRandomProvider and then advances the state of the current instance. The copy is returned.

      The current state will be advanced in a single operation by the equivalent of a number of sequential calls to a method that updates the state of the provider. The size of the long jump is implementation dependent.

      Repeat invocations of this method will create a series of generators that are uniformly spaced at intervals of the output sequence. Each generator provides non-overlapping output for the length of the long jump for use in parallel computations.

      The returned copy may be jumped m / n times before overlap with the current instance where m is the long jump length and n is the jump length of the JumpableUniformRandomProvider.jump() method.

      The jump size is the equivalent of 296 calls to nextLong(). It can provide up to 232 non-overlapping subsequences of length 296; each subsequence can provide up to 232 non-overlapping subsequences of length 264 using the AbstractXoRoShiRo128.jump() method.

      Specified by:
      longJump in interface LongJumpableUniformRandomProvider
      Overrides:
      longJump in class AbstractXoRoShiRo128
      Returns:
      A copy of the current state.

    • copy

      protected XoRoShiRo128PlusPlus copy()
      Create a copy.
      Specified by:
      copy in class AbstractXoRoShiRo128
      Returns:
      the copy