Struct SimRng 

pub struct SimRng { /* private fields */ }

Seeded RNG wrapper for deterministic simulation

Implementations

impl SimRng

pub fn new(seed: u64) -> Self

Create a new RNG with the given seed

pub fn gen_range<T, R>(&mut self, range: R) -> T

where T: SampleUniform, R: SampleRange<T>,

Generate a random value in the given range

pub fn gen_f64(&mut self) -> f64

Generate a random f64 in [0, 1)

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

Generate a random bool with the given probability of true

pub fn exponential(&mut self, rate: f64) -> f64

Generate an exponential random variable

Used for inter-arrival times in Poisson processes. Mean = 1/rate

pub fn poisson(&mut self, lambda: f64) -> u32

Generate a Poisson random variable

Returns the number of events in a unit interval given the rate.

pub fn negbin(&mut self, mean: f64, dispersion: f64) -> u32

Generate from a negative binomial distribution

Used for order line counts. Returns at least 1. Uses Gamma-Poisson mixture.

pub fn zipf(&mut self, n: usize, alpha: f64) -> usize

Generate from a Zipf distribution

Used for SKU popularity. Returns an index in [0, n).

pub fn normal(&mut self, mean: f64, stddev: f64) -> f64

Generate a normal random variable

pub fn lognormal(&mut self, mean: f64, stddev: f64) -> f64

Generate a lognormal random variable

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

Generate a uniform random variable

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

Choose a random element from a slice

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

Shuffle a slice in place

Trait Implementations

impl Debug for SimRng

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

Formats the value using the given formatter.