Struct rand_distr::Binomial

pub struct Binomial { /* private fields */ }

The binomial distribution Binomial(n, p).

The binomial distribution is a discrete probability distribution which describes the probability of seeing k successes in n independent trials, each of which has success probability p.

Density function

f(k) = n!/(k! (n-k)!) p^k (1-p)^(n-k) for k >= 0.

Known issues

See documentation of Binomial::new.

Plot

The following plot of the binomial distribution illustrates the probability of k successes out of n = 10 trials with p = 0.2 and p = 0.6 for 0 <= k <= n.

Example

use rand_distr::{Binomial, Distribution};

let bin = Binomial::new(20, 0.3).unwrap();
let v = bin.sample(&mut rand::thread_rng());
println!("{} is from a binomial distribution", v);

Implementations

impl Binomial

pub fn new(n: u64, p: f64) -> Result<Binomial, Error>

Construct a new Binomial with the given shape parameters n (number of trials) and p (probability of success).

Known issues

Although this method should return an Error on invalid parameters, some (extreme) parameter combinations are known to return a Binomial object which panics when sampled. See #1378.

Trait Implementations

impl Clone for Binomial

fn clone(&self) -> Binomial

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for Binomial

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for Binomial

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

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Distribution<u64> for Binomial

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) -> DistIter<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) -> DistMap<Self, F, T, S>

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

Create a distribution of values of ‘S’ by mapping the output of Self through the closure F

impl PartialEq for Binomial

fn eq(&self, other: &Binomial) -> 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 Serialize for Binomial

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

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl Copy for Binomial

impl StructuralPartialEq for Binomial