Struct DiscreteDistribution 

pub struct DiscreteDistribution {
    pub pmf: Vec<f64>,
}

A discrete probability distribution backed by an explicit PMF table.

Sampling uses an LCG (linear congruential generator) seeded by the caller.

Fields

pmf: Vec<f64>

PMF values (must sum to 1).

Implementations

impl DiscreteDistribution

pub fn from_weights(weights: &[f64]) -> Self

Creates a DiscreteDistribution from raw weights, normalising them.

pub fn prob(&self, k: usize) -> f64

Returns the PMF value at index k.

pub fn sample(&self, u: f64) -> usize

Draws a sample using an LCG random number in [0, 1).

Pass successive LCG outputs as u to simulate multiple draws.

pub fn mean(&self) -> f64

Computes the mean (E[X]).

pub fn variance(&self) -> f64

Computes the variance (Var[X]).

pub fn shannon_entropy(&self) -> f64

Computes the Shannon entropy H = -Σ p log p (nats).