gam-problem 0.3.127

Neutral solver/criterion contract types for the gam penalized-likelihood engine
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36

//! Dispersion/scale contract used by covariance and reference-distribution code.

use serde::{Deserialize, Serialize};

/// Dispersion contract used by inferential covariance and reference distributions.
///
/// `Known(phi)` is used for fixed-scale exponential-family fits such as
/// Poisson and Binomial (`phi = 1`). `Estimated(phi)` is used when the
/// residual/likelihood scale is estimated from the data, e.g. Gaussian
/// (`phi = sigma^2`) and Gamma (`phi = 1 / shape`). Stored covariance
/// matrices are scaled by this `phi`.
#[derive(Clone, Copy, Debug, PartialEq, Serialize, Deserialize)]
pub enum Dispersion {
    Known(f64),
    Estimated(f64),
}

impl Dispersion {
    #[inline]
    pub const fn phi(self) -> f64 {
        match self {
            Self::Known(phi) | Self::Estimated(phi) => phi,
        }
    }

    #[inline]
    pub const fn is_estimated(self) -> bool {
        matches!(self, Self::Estimated(_))
    }
}

impl Default for Dispersion {
    fn default() -> Self {
        Self::Known(1.0)
    }
}