Struct GammaRatePosterior 

pub struct GammaRatePosterior {
    pub shape: f64,
    pub rate: f64,
}

Conjugate Gamma(shape, rate) posterior over a Poisson rate λ.

Fields

shape: f64

Shape parameter.

rate: f64

Rate parameter (inverse scale).

Implementations

impl GammaRatePosterior

pub fn new(shape: f64, rate: f64) -> Self

Create a Gamma(shape, rate) prior. Both parameters must be positive.

pub fn observe(&mut self, count: u64, exposure: f64)

Conjugate Gamma–Poisson update: observe count events over exposure units of exposure (shape += count, rate += exposure).

pub fn mean(&self) -> f64

Posterior mean shape / rate.

pub fn sample<R: Rng>(&self, rng: &mut R) -> f64

Draw λ ~ Gamma(shape, rate) from the current posterior.

Trait Implementations

impl Clone for GammaRatePosterior

fn clone(&self) -> GammaRatePosterior

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for GammaRatePosterior

impl Debug for GammaRatePosterior

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

Formats the value using the given formatter.

impl PartialEq for GammaRatePosterior

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for GammaRatePosterior