Enum Link 

pub enum Link {
    Identity,
    Log,
    Logit,
    Probit,
    Cloglog,
    Inverse,
    InverseSquared,
    Power(f64),
}

A link function η = g(μ), with its inverse and derivative.

A closed enum, so a fitted model’s link serializes as data.

use prospicio_models::Link;

let g = Link::Log;
assert!((g.inverse(g.link(3.0)) - 3.0).abs() < 1e-15);
assert_eq!(g.mu_eta(0.0), 1.0);

Variants

Identity

η = μ.

Log

η = ln μ: multiplicative models, the actuarial default.

Logit

η = ln(μ / (1 - μ)).

Probit

η = Φ⁻¹(μ).

Cloglog

η = ln(-ln(1 - μ)).

Inverse

η = 1 / μ, the gamma family’s canonical link.

InverseSquared

η = 1 / μ², the inverse Gaussian’s canonical link.

Power(f64)

η = μ^λ for λ ≠ 0 (λ = 0 is the log link).

Implementations

impl Link

pub fn link(&self, mu: f64) -> f64

η = g(μ).

pub fn inverse(&self, eta: f64) -> f64

μ = g⁻¹(η).

pub fn mu_eta(&self, eta: f64) -> f64

dμ/dη at η.

pub fn mu_eta2(&self, eta: f64) -> f64

d²μ/dη² at η, for the observed information of a non-canonical link.

pub fn valid_eta(&self, eta: f64) -> bool

Whether η maps to a mean the link can produce (for example, a positive η under the inverse link).

Trait Implementations

impl Clone for Link

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for Link

impl Debug for Link

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

Formats the value using the given formatter.

impl PartialEq for Link

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for Link