# Struct rand_distr::Dirichlet

``````pub struct Dirichlet<F, const N: usize>where
F: Float,
StandardNormal: Distribution<F>,
Exp1: Distribution<F>,
Open01: Distribution<F>,{ /* private fields */ }``````
Expand description

The Dirichlet distribution `Dirichlet(α₁, α₂, ..., αₖ)`.

The Dirichlet distribution is a family of continuous multivariate probability distributions parameterized by a vector of positive real numbers `α₁, α₂, ..., αₖ`, where `k` is the number of dimensions of the distribution. The distribution is supported on the `k-1`-dimensional simplex, which is the set of points `x = [x₁, x₂, ..., xₖ]` such that `0 ≤ xᵢ ≤ 1` and `∑ xᵢ = 1`. It is a multivariate generalization of the `Beta` distribution. The distribution is symmetric when all `αᵢ` are equal.

## §Plot

The following plot illustrates the 2-dimensional simplices for various 3-dimensional Dirichlet distributions.

## §Example

``````use rand::prelude::*;
use rand_distr::Dirichlet;

let dirichlet = Dirichlet::new([1.0, 2.0, 3.0]).unwrap();
println!("{:?} is from a Dirichlet([1.0, 2.0, 3.0]) distribution", samples);``````

## Implementations§

source§

### impl<F, const N: usize> Dirichlet<F, N>where F: Float, StandardNormal: Distribution<F>, Exp1: Distribution<F>, Open01: Distribution<F>,

source

#### pub fn new(alpha: [F; N]) -> Result<Dirichlet<F, N>, Error>

Construct a new `Dirichlet` with the given alpha parameter `alpha`.

Requires `alpha.len() >= 2`, and each value in `alpha` must be positive, finite and not subnormal.

## Trait Implementations§

source§

### impl<F, const N: usize> Clone for Dirichlet<F, N>where F: Float + Clone, StandardNormal: Distribution<F>, Exp1: Distribution<F>, Open01: Distribution<F>,

source§

#### fn clone(&self) -> Dirichlet<F, N>

Returns a copy of the value. Read more
1.0.0 · source§

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

Performs copy-assignment from `source`. Read more
source§

### impl<F, const N: usize> Debug for Dirichlet<F, N>where F: Float + Debug, StandardNormal: Distribution<F>, Exp1: Distribution<F>, Open01: Distribution<F>,

source§

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

Formats the value using the given formatter. Read more
source§

### impl<F, const N: usize> Distribution<[F; N]> for Dirichlet<F, N>where F: Float, StandardNormal: Distribution<F>, Exp1: Distribution<F>, Open01: Distribution<F>,

source§

#### fn sample<R: Rng + ?Sized>(&self, rng: &mut R) -> [F; N]

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

#### 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. Read more
source§

#### 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` Read more
source§

### impl<F, const N: usize> PartialEq for Dirichlet<F, N>where F: Float + PartialEq, StandardNormal: Distribution<F>, Exp1: Distribution<F>, Open01: Distribution<F>,

source§

#### fn eq(&self, other: &Dirichlet<F, N>) -> bool

Tests for `self` and `other` values to be equal, and is used by `==`.
1.0.0 · source§

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

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

§

§

§

§

§

§

## Blanket Implementations§

source§

### impl<T> Any for Twhere T: 'static + ?Sized,

source§

#### fn type_id(&self) -> TypeId

Gets the `TypeId` of `self`. Read more
source§

### impl<T> Borrow<T> for Twhere T: ?Sized,

source§

#### fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more
source§

### impl<T> BorrowMut<T> for Twhere T: ?Sized,

source§

#### fn borrow_mut(&mut self) -> &mut T

Mutably borrows from an owned value. Read more
source§

### impl<T> CloneToUninit for Twhere T: Clone,

source§

#### unsafe fn clone_to_uninit(&self, dst: *mut T)

🔬This is a nightly-only experimental API. (`clone_to_uninit`)
Performs copy-assignment from `self` to `dst`. Read more
source§

### impl<T> From<T> for T

source§

#### fn from(t: T) -> T

Returns the argument unchanged.

source§

### impl<T, U> Into<U> for Twhere U: From<T>,

source§

#### fn into(self) -> U

Calls `U::from(self)`.

That is, this conversion is whatever the implementation of `From<T> for U` chooses to do.

source§

### impl<T> ToOwned for Twhere T: Clone,

source§

#### type Owned = T

The resulting type after obtaining ownership.
source§

#### fn to_owned(&self) -> T

Creates owned data from borrowed data, usually by cloning. Read more
source§

#### fn clone_into(&self, target: &mut T)

Uses borrowed data to replace owned data, usually by cloning. Read more
source§

### impl<T, U> TryFrom<U> for Twhere U: Into<T>,

source§

#### type Error = Infallible

The type returned in the event of a conversion error.
source§

#### fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

Performs the conversion.
source§

### impl<T, U> TryInto<U> for Twhere U: TryFrom<T>,

source§

#### type Error = <U as TryFrom<T>>::Error

The type returned in the event of a conversion error.
source§

#### fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

Performs the conversion.
source§

source§