Struct rand_distr::Exp

pub struct Exp<F>
where
    F: Float,
    Exp1: Distribution<F>,
{ /* private fields */ }

The exponential distribution Exp(lambda).

This distribution has density function: f(x) = lambda * exp(-lambda * x) for x > 0, when lambda > 0. For lambda = 0, all samples yield infinity.

Note that Exp1 is an optimised implementation for lambda = 1.

Example

use rand_distr::{Exp, Distribution};

let exp = Exp::new(2.0).unwrap();
let v = exp.sample(&mut rand::thread_rng());
println!("{} is from a Exp(2) distribution", v);

Implementations

impl<F> Exp<F>

where F: Float, Exp1: Distribution<F>,

pub fn new(lambda: F) -> Result<Exp<F>, Error>

Construct a new Exp with the given shape parameter lambda.

Remarks

For custom types N implementing the Float trait, the case lambda = 0 is handled as follows: each sample corresponds to a sample from an Exp1 multiplied by 1 / 0. Primitive types yield infinity, since 1 / 0 = infinity.

Trait Implementations

impl<F> Clone for Exp<F>

where F: Float + Clone, Exp1: Distribution<F>,

fn clone(&self) -> Exp<F>

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<F> Debug for Exp<F>

where F: Float + Debug, Exp1: Distribution<F>,

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

Formats the value using the given formatter.

impl<F> Distribution<F> for Exp<F>

where F: Float, Exp1: Distribution<F>,

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

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<F> Copy for Exp<F>

where F: Float + Copy, Exp1: Distribution<F>,