Struct rv::dist::SymmetricDirichlet

pub struct SymmetricDirichlet { /* fields omitted */ }

Symmetric Dirichlet distribution where all alphas are the same.

SymmetricDirichlet { alpha, k } is mathematicall equivalent to Dirichlet { alphas: vec![alpha; k] }. This version has some extra optimizations to seep up computing the PDF and drawing random vectors.

Methods

impl SymmetricDirichlet

pub fn set_alpha(&mut self, val: f64) -> &mut Self

impl SymmetricDirichlet

pub fn new(alpha: f64, k: usize) -> Result<Self, DirichletError>

Create a new symmetric Dirichlet distributon

Arguments

• alpha: The Dirichlet weight.
• k : The number of weights. alpha will be replicated k times.

pub fn new_unchecked(alpha: f64, k: usize) -> Self

Create a new SymmetricDirichlet without checking whether the parmaeters are valid.

pub fn jeffreys(k: usize) -> Result<Self, DirichletError>

The Jeffrey's Dirichlet prior for Categorical distributions

Example

let symdir = SymmetricDirichlet::jeffreys(4).unwrap();
assert_eq!(symdir, SymmetricDirichlet::new(0.5, 4).unwrap());

pub fn alpha(&self) -> f64

Get the alpha unfiorm weight parameter

Example

let symdir = SymmetricDirichlet::new(1.2, 5).unwrap();
assert_eq!(symdir.alpha(), 1.2);

pub fn k(&self) -> usize

Get the number of weights, k

Example

let symdir = SymmetricDirichlet::new(1.2, 5).unwrap();
assert_eq!(symdir.k(), 5);

Trait Implementations

impl Clone for SymmetricDirichlet

fn clone(&self) -> SymmetricDirichlet

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<X: CategoricalDatum> ConjugatePrior<X, Categorical> for SymmetricDirichlet

type Posterior = Dirichlet

fn posterior(&self, x: &CategoricalData<X>) -> Self::Posterior

Computes the posterior distribution from the data

fn ln_m(&self, x: &CategoricalData<X>) -> f64

Log marginal likelihood

fn ln_pp(&self, y: &X, x: &CategoricalData<X>) -> f64

Log posterior predictive of y given x

fn m(&self, x: &DataOrSuffStat<X, Fx>) -> f64

Marginal likelihood of x

fn pp(&self, y: &X, x: &DataOrSuffStat<X, Fx>) -> f64

Posterior Predictive distribution

impl ContinuousDistr<Vec<f64>> for SymmetricDirichlet

fn pdf(&self, x: &X) -> f64

The value of the Probability Density Function (PDF) at x

fn ln_pdf(&self, x: &X) -> f64

The value of the log Probability Density Function (PDF) at x

impl Debug for SymmetricDirichlet

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

Formats the value using the given formatter.

impl Display for SymmetricDirichlet

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

Formats the value using the given formatter.

impl<'_> From<&'_ SymmetricDirichlet> for String

fn from(symdir: &SymmetricDirichlet) -> String

Performs the conversion.

impl<'_> From<&'_ SymmetricDirichlet> for Dirichlet

fn from(symdir: &SymmetricDirichlet) -> Self

Performs the conversion.

impl From<SymmetricDirichlet> for Dirichlet

fn from(symdir: SymmetricDirichlet) -> Self

Performs the conversion.

impl PartialEq<SymmetricDirichlet> for SymmetricDirichlet

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

This method tests for self and other values to be equal, and is used by ==.

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

This method tests for !=.

impl PartialOrd<SymmetricDirichlet> for SymmetricDirichlet

fn partial_cmp(&self, other: &SymmetricDirichlet) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &SymmetricDirichlet) -> bool

This method tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &SymmetricDirichlet) -> bool

This method tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &SymmetricDirichlet) -> bool

This method tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &SymmetricDirichlet) -> bool

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl Rv<Categorical> for SymmetricDirichlet

fn ln_f(&self, x: &Categorical) -> f64

Probability function

fn draw<R: Rng>(&self, rng: &mut R) -> Categorical

Single draw from the Rv

fn f(&self, x: &X) -> f64

Probability function

fn sample<R: Rng>(&self, n: usize, rng: &mut R) -> Vec<X>

Multiple draws of the Rv

impl Rv<Vec<f64>> for SymmetricDirichlet

fn draw<R: Rng>(&self, rng: &mut R) -> Vec<f64>

Single draw from the Rv

fn ln_f(&self, x: &Vec<f64>) -> f64

Probability function

fn f(&self, x: &X) -> f64

Probability function

fn sample<R: Rng>(&self, n: usize, rng: &mut R) -> Vec<X>

Multiple draws of the Rv

impl StructuralPartialEq for SymmetricDirichlet

impl Support<Vec<f64>> for SymmetricDirichlet

fn supports(&self, x: &Vec<f64>) -> bool

Returns true if x is in the support of the Rv