Struct xorshift::xorshift128::Xorshift128

pub struct Xorshift128(_);

A random number generator that uses the xorshift128+ algorithm [1].

Description

Quoted from [1].

This generator has been replaced by xoroshiro128plus, which is significantly faster and has better statistical properties.

It might be nonetheless useful for languages in which low-level rotate instructions are not available. Due to the relatively short period it is acceptable only for applications with a mild amount of parallelism; otherwise, use a xorshift1024* generator.

Note that the lowest bit of this generator is an LSFR, and thus it is slightly less random than the other bits. We suggest to use a sign test to extract a random Boolean value.

The state must be seeded so that it is not everywhere zero. If you have a 64-bit seed, we suggest to seed a splitmix64 generator and use its output to fill s.

[1]: Sebastiano Vigna, xorshift128+

Parallelism

The RngJump implementation is equivalent to 2⁶⁴ calls to next_u64(). Used to generate 2⁶⁴ non-overlapping subsequences for parallel computations.

Trait Implementations

impl Copy for Xorshift128

impl Clone for Xorshift128

fn clone(&self) -> Xorshift128

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Rng for Xorshift128

fn next_u32(&mut self) -> u32

Return the next random u32.

fn next_u64(&mut self) -> u64

Return the next random u64.

fn next_f32(&mut self) -> f32

Return the next random f32 selected from the half-open interval [0, 1).

fn next_f64(&mut self) -> f64

Return the next random f64 selected from the half-open interval [0, 1).

fn fill_bytes(&mut self, dest: &mut [u8])

Fill dest with random data.

fn gen<T>(&mut self) -> T where
    T: Rand, 

Return a random value of a Rand type.

fn gen_iter<T>(&'a mut self) -> Generator<'a, T, Self> where
    T: Rand, 

Return an iterator that will yield an infinite number of randomly generated items.

fn gen_range<T>(&mut self, low: T, high: T) -> T where
    T: SampleRange + PartialOrd<T>, 

Generate a random value in the range [low, high).

fn gen_weighted_bool(&mut self, n: u32) -> bool

Return a bool with a 1 in n chance of true

fn gen_ascii_chars(&'a mut self) -> AsciiGenerator<'a, Self>

Return an iterator of random characters from the set A-Z,a-z,0-9.

fn choose<T>(&mut self, values: &'a [T]) -> Option<&'a T>

Return a random element from values.

fn choose_mut<T>(&mut self, values: &'a mut [T]) -> Option<&'a mut T>

Return a mutable pointer to a random element from values.

fn shuffle<T>(&mut self, values: &mut [T])

Shuffle a mutable slice in place.

impl<'a> SeedableRng<&'a [u64]> for Xorshift128

fn reseed(&mut self, seed: &'a [u64])

Reseed an RNG with the given seed.

fn from_seed(seed: &'a [u64]) -> Xorshift128

Create a new RNG with the given seed.

impl Rand for Xorshift128

fn rand<R: Rng>(other: &mut R) -> Xorshift128

Generates a random instance of this type using the specified source of randomness.

impl RngJump for Xorshift128

fn jump(&mut self, count: usize)

Forward the state of the random number generator.