components.bage_mod: Extract Values for Hyper-Parameters

In bage: Bayesian Estimation and Forecasting of Age-Specific Rates

Extract Values for Hyper-Parameters

Description

Extract values for hyper-parameters from a model object. Hyper-parameters include main effects and interactions, dispersion and variance terms, and SVD or spline coefficients.

Usage

## S3 method for class 'bage_mod'
components(object, quiet = FALSE, ...)

Arguments

object	Object of class "bage_mod", typically created with mod_pois(), mod_binom(), or mod_norm().
quiet	Whether to suppress messages. Default is FALSE.
...	Unused. Included for generic consistency only.

Value

A tibble with four columns columns:

The return value contains the following columns:

• term Model term that the hyper-parameter belongs to.

• component Component within term.

• level Element within component .

• .fitted An rvec containing draws from the posterior distribution.

Fitted vs unfitted models

components() is typically called on a fitted model. In this case, the modelled values are draws from the joint posterior distribution for the hyper-parameters in the model.

components() can, however, be called on an unfitted model. In this case, the modelled values are draws from the joint prior distribution. In other words, the modelled values are informed by model priors, and by any exposure, size, or weights argument in the model, but not by the observed outcomes.

See Also

• augment() Extract data and values for rates, means, or probabilities

• tidy() Extract a one-line summary of a model

• mod_pois() Specify a Poisson model

• mod_binom() Specify a binomial model

• mod_norm() Specify a normal model

• fit() Fit a model

• is_fitted() See if a model has been fitted

• unfit() Reset a model

Examples

## specify model
mod <- mod_pois(injuries ~ age + sex + year,
                data = nzl_injuries,
                exposure = popn)

## extract prior distribution
## of hyper-parameters
mod |>
  components()

## fit model
mod <- mod |>
  fit()

## extract posterior distribution
## of hyper-parameters
mod |>
  components()

bage documentation built on April 3, 2025, 8:53 p.m.