Struct SimRng 

pub struct SimRng {
    state: u64,
}

Deterministic xorshift64 RNG seeded by FNV-1a over a simulation identity.

Fields

state: u64

Implementations

impl SimRng

fn new_state(seed: u64) -> Self

pub fn for_iteration( seed_base: u64, chunk_id: &str, iteration_index: u32, ) -> Self

Constructs the stable stream for a simulation iteration.

The base seed and iteration index are hashed in little-endian byte order; the chunk identifier is hashed as its exact UTF-8 bytes.

pub fn from_prefix(prefix: u64, iteration_index: u32) -> Self

Constructs a stable iteration stream from a seed_prefix result.

pub fn next_u64(&mut self) -> u64

Advances the xorshift64 state and returns the next 64-bit draw.

pub fn next_f64(&mut self) -> f64

Returns a uniform f64 in [0.0, 1.0) using the high 53 bits of one draw.

pub fn next_bool_at_prob(&mut self, p: f64) -> bool

Returns true with fractional probability p.

pub fn range_u32(&mut self, minimum: u32, maximum: u32) -> u32

Samples an integer uniformly from [minimum, maximum).

pub fn gaussian(&mut self, mean: f64, standard_deviation: f64) -> f64

Samples a Gaussian value with the Box-Muller transform.

Trait Implementations

impl Debug for SimRng

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

Formats the value using the given formatter.