Xoshiro256PlusPlusEngine Structure

Represents a Xoshiro256++ random number generator engine with 64-bit output.

Definition

Namespace: Numerics.NET.Random.Engines
Assembly: Numerics.NET (in Numerics.NET.dll) Version: 10.3.0
C#
public struct Xoshiro256PlusPlusEngine : IScalarEngine<ulong>, 
	IRandomEngine, IStateful, IAdvanceable, IJumpable
Inheritance
Object  →  ValueType  →  Xoshiro256PlusPlusEngine
Implements
IRandomEngine, IScalarEngine<UInt64>, IAdvanceable, IJumpable, IStateful

Remarks

The Xoshiro256++ (Xor-Shift-Rotate 256 Plus-Plus) engine is a 64-bit all-purpose random number generator by David Blackman and Sebastiano Vigna. It features a 256-bit state with a period of 2256 - 1 and passes all statistical tests.

Algorithm Details:

  • State size: 256 bits (4 × 64-bit words)
  • Output function: ++ (Plus-Plus) scrambler: rotl(s[0] + s[3], 23) + s[0]
  • Period: 2256 - 1
  • Performance: Excellent speed and statistical quality

Compatibility:

This is one of the fastest high-quality 64-bit generators available, combining the benefits of both Xoshiro256** and Xoshiro256+.

Use Cases:

The "++" scrambler provides excellent statistical properties for all use cases, making it an ideal general-purpose choice for simulations, games, and Monte Carlo methods.

Reference: David Blackman and Sebastiano Vigna. "Scrambled Linear Pseudorandom Number Generators." ACM Trans. Math. Softw. 2021.

See also: https://prng.di.unimi.it/

Example

C#
var engine = new Xoshiro256PlusPlusEngine();
engine.Seed(SeedSequences.SplitMix64(123));

ulong value = engine.Next();

ulong[] values = new ulong[100];
engine.Fill(values);

// Jump for parallel streams
engine.Jump();

Properties

BitsPerWord Gets the native word size in bits.
JumpSize Gets the size category of the primary jump operation.
LongJumpSize Gets the size category of the long jump operation.
Name Gets a human-readable name for this engine.
StateSize Gets the number of bytes required to save/load this engine's state.

Methods

Advance() Advances the engine state by one transition step.
Advance(UInt64) Advances the RNG state by the specified number of outputs.
EqualsIndicates whether this instance and a specified object are equal.
(Inherited from ValueType)
Fill Fills the destination span with successive native words from the engine's stream.
GetHashCodeReturns the hash code for this instance.
(Inherited from ValueType)
GetTypeGets the Type of the current instance.
(Inherited from Object)
Jump Jumps the RNG forward by the specified number of primary jump strides.
LoadState Loads the engine's state from the source span in a stable little-endian format.
LongJump Jumps the RNG forward by the specified number of long jump strides.
Next Advances the engine by one step and returns the native word produced for that step.
Output Returns the native word produced by applying the output mapping function to the current engine state, without mutating that state.
SaveState Saves the engine's state to the destination span in a stable little-endian format.
Seed(SeedSequence) Initializes the engine state from a seed sequence.
Seed(UInt64, UInt64, UInt64, UInt64) Directly sets the four 64-bit state words.
ToStringReturns the fully qualified type name of this instance.
(Inherited from ValueType)

See Also