Struct Hypergeometric

pub struct Hypergeometric { /* private fields */ }

The hypergeometric distribution Hypergeometric(N, K, n).

This is the distribution of successes in samples of size n drawn without replacement from a population of size N containing K success states.

See the binomial distribution for the analogous distribution for sampling with replacement. It is a good approximation when the population size is much larger than the sample size.

Density function

f(k) = binomial(K, k) * binomial(N-K, n-k) / binomial(N, n), where binomial(a, b) = a! / (b! * (a - b)!).

Plot

The following plot of the hypergeometric distribution illustrates the probability of drawing k successes in n = 10 draws from a population of N = 50 items, of which either K = 12 or K = 35 are successes.

Example

use rand_distr::{Distribution, Hypergeometric};

let hypergeo = Hypergeometric::new(60, 24, 7).unwrap();
let v = hypergeo.sample(&mut rand::rng());
println!("{} is from a hypergeometric distribution", v);

Implementations

impl Hypergeometric

pub fn new( total_population_size: u64, population_with_feature: u64, sample_size: u64, ) -> Result<Self, Error>

Constructs a new Hypergeometric with the shape parameters N = total_population_size, K = population_with_feature, n = sample_size.

Trait Implementations

impl Clone for Hypergeometric

fn clone(&self) -> Hypergeometric

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for Hypergeometric

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

Formats the value using the given formatter.

impl Distribution<u64> for Hypergeometric

fn sample<R: Rng + ?Sized>(&self, rng: &mut R) -> u64

Generate a random value of T, using rng as the source of randomness.

fn sample_iter<R>(self, rng: R) -> Iter<Self, R, T>

where R: Rng, Self: Sized,

Create an iterator that generates random values of T, using rng as the source of randomness.

fn map<F, S>(self, func: F) -> Map<Self, F, T, S>

where F: Fn(T) -> S, Self: Sized,

Map sampled values to type S

impl PartialEq for Hypergeometric

fn eq(&self, other: &Hypergeometric) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Copy for Hypergeometric

impl StructuralPartialEq for Hypergeometric