Crate rand_pcg

source ·
Expand description

The PCG random number generators.

This is a native Rust implementation of a small selection of PCG generators. The primary goal of this crate is simple, minimal, well-tested code; in other words it is explicitly not a goal to re-implement all of PCG.

This crate provides:

  • Pcg32 aka Lcg64Xsh32, officially known as pcg32, a general purpose RNG. This is a good choice on both 32-bit and 64-bit CPUs (for 32-bit output).
  • Pcg64 aka Lcg128Xsl64, officially known as pcg64, a general purpose RNG. This is a good choice on 64-bit CPUs.
  • Pcg64Mcg aka Mcg128Xsl64, officially known as pcg64_fast, a general purpose RNG using 128-bit multiplications. This has poor performance on 32-bit CPUs but is a good choice on 64-bit CPUs for both 32-bit and 64-bit output.

Both of these use 16 bytes of state and 128-bit seeds, and are considered value-stable (i.e. any change affecting the output given a fixed seed would be considered a breaking change to the crate).

§Example

To initialize a generator, use the SeedableRng trait:

use rand_core::{SeedableRng, RngCore};
use rand_pcg::Pcg64Mcg;

let mut rng = Pcg64Mcg::seed_from_u64(0);
let x: u32 = rng.next_u32();

The functionality of this crate is implemented using traits from the rand_core crate, but you may use the rand crate for further functionality to initialize the generator from various sources and to generate random values:

ⓘ
use rand::{Rng, SeedableRng};
use rand_pcg::Pcg64Mcg;

let mut rng = Pcg64Mcg::from_entropy();
let x: f64 = rng.gen();

Structs§

  • Lcg64Xsh32
    A PCG random number generator (XSH RR 64/32 (LCG) variant).
  • Lcg128CmDxsm64
    A PCG random number generator (CM DXSM 128/64 (LCG) variant).
  • Lcg128Xsl64
    A PCG random number generator (XSL RR 128/64 (LCG) variant).
  • Mcg128Xsl64
    A PCG random number generator (XSL 128/64 (MCG) variant).

Type Aliases§