Struct SimRng 

pub struct SimRng { /* private fields */ }

Deterministic, reproducible random number generator.

Based on PCG (Permuted Congruential Generator) which provides:

• Excellent statistical properties
• Fast generation
• Predictable sequences from seed
• Independent streams via partitioning

Implementations

impl SimRng

pub fn new(master_seed: u64) -> Self

Create a new RNG with the given master seed.

pub const fn master_seed(&self) -> u64

Get the master seed.

pub const fn stream(&self) -> u64

Get current stream index.

pub fn partition(&mut self, n: usize) -> Vec<Self>

Create partitioned RNGs for parallel execution.

Each partition gets an independent stream derived from the master seed, ensuring reproducibility regardless of execution order.

Example

use simular::engine::rng::SimRng;

let mut rng = SimRng::new(42);
let partitions = rng.partition(4);
assert_eq!(partitions.len(), 4);

pub fn gen_f64(&mut self) -> f64

Generate a random f64 in [0, 1).

pub fn gen_range_f64(&mut self, min: f64, max: f64) -> f64

Generate a random f64 in the given range.

Panics

Panics if min > max.

pub fn gen_u64(&mut self) -> u64

Generate a random u64.

pub fn sample_n(&mut self, n: usize) -> Vec<f64>

Generate n random f64 samples in [0, 1).

pub fn gen_standard_normal(&mut self) -> f64

Generate a standard normal sample using Box-Muller transform.

pub fn gen_normal(&mut self, mean: f64, std: f64) -> f64

Generate a normal sample with given mean and std.

pub fn state_bytes(&self) -> Vec<u8>

Get RNG state as bytes for hashing (audit logging).

Returns a deterministic byte representation of the RNG state.

pub fn save_state(&self) -> RngState

Save RNG state for checkpoint.

Note: PCG internal state is not directly serializable, so we save enough information to recreate the RNG at the same point in the stream.

pub fn restore_state(&mut self, state: &RngState) -> Result<(), RngRestoreError>

Restore RNG state from checkpoint.

Errors

Returns error if state cannot be restored.

Trait Implementations

impl Clone for SimRng

fn clone(&self) -> SimRng

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for SimRng

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for SimRng

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Serialize for SimRng

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.