Class AbstractXoRoShiRo1024

java.lang.Object
org.apache.commons.rng.core.BaseProvider
org.apache.commons.rng.core.source64.LongProvider
org.apache.commons.rng.core.source64.AbstractXoRoShiRo1024
All Implemented Interfaces:
RandomLongSource, JumpableUniformRandomProvider, LongJumpableUniformRandomProvider, RestorableUniformRandomProvider, UniformRandomProvider
Direct Known Subclasses:
XoRoShiRo1024PlusPlus, XoRoShiRo1024Star, XoRoShiRo1024StarStar
abstract class AbstractXoRoShiRo1024 extends LongProvider implements LongJumpableUniformRandomProvider
This abstract class is a base for algorithms from the Xor-Shift-Rotate family of 64-bit generators with 1024-bits of state.
Since:
1.3
See Also:

  • Field Details

    • SEED_SIZE

      private static final int SEED_SIZE
      Size of the state vector.
      See Also:

    • 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.

    • state

      private final long[] state
      State.

    • index

      private int index
      Index in "state" array.

  • Constructor Details

    • AbstractXoRoShiRo1024

      AbstractXoRoShiRo1024(long[] seed)
      Creates a new instance.
      Parameters:
      seed - Initial seed. If the length is larger than 16, only the first 16 elements will be used; if smaller, the remaining elements will be automatically set. A seed containing all zeros will create a non-functional generator.

    • AbstractXoRoShiRo1024

      protected AbstractXoRoShiRo1024(AbstractXoRoShiRo1024 source)
      Creates a copy instance.
      Parameters:
      source - Source to copy.

  • Method Details

    • getStateInternal

      protected byte[] getStateInternal()
      Creates a snapshot of the RNG state.
      Overrides:
      getStateInternal in class LongProvider
      Returns:
      the internal state.

    • setStateInternal

      protected void setStateInternal(byte[] s)
      Resets the RNG to the given state.
      Overrides:
      setStateInternal in class LongProvider
      Parameters:
      s - State (previously obtained by a call to BaseProvider.getStateInternal()).
      See Also:

    • setSeedInternal

      private void setSeedInternal(long[] seed)
      Seeds the RNG.
      Parameters:
      seed - Seed.

    • next

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

    • transform

      protected abstract long transform(long s0, long s15)
      Transform the two consecutive 64-bit states of the generator to a 64-bit output. The transformation function shall vary with respect to different generators.
      Parameters:
      s0 - The current state.
      s15 - The previous state.
      Returns:
      the 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 2512 calls to nextLong(). It can provide up to 2512 non-overlapping subsequences.

      Specified by:
      jump in interface JumpableUniformRandomProvider
      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 2768 calls to nextLong(). It can provide up to 2256 non-overlapping subsequences of length 2768; each subsequence can provide up to 2256 non-overlapping subsequences of length 2512 using the jump() method.

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

    • copy

      protected abstract AbstractXoRoShiRo1024 copy()
      Create a copy.
      Returns:
      the copy

    • performJump

      private void performJump(long[] jumpCoefficients)
      Perform the jump to advance the generator state. Resets the cached state of the generator.
      Parameters:
      jumpCoefficients - the jump coefficients