pp_check.bmmfit: Posterior predictive check for bmmfit objects

In bmm: Easy and Accessible Bayesian Measurement Models Using 'brms'

Posterior predictive check for bmmfit objects

Description

For models where brms provides pp_check support, this method delegates to brms::pp_check(). For models with multinomial families (e.g., the m3 model), brms's pp_check is unavailable; this method dispatches to a model-specific visualisation instead.

Usage

## S3 method for class 'bmmfit'
pp_check(object, type = "dens_overlay", ndraws = NULL, group = NULL, ...)

Arguments

object	A bmmfit object returned by bmm().
type	Character. Type of pp_check (default "dens_overlay"). For non-multinomial models, passed to brms::pp_check(). When group is specified, the grouped variant (e.g., "dens_overlay_grouped") is auto-selected if available. Multinomial models produce a response proportion profile regardless of the value supplied.
ndraws	Integer. Number of posterior draws. Defaults to 100 for multinomial models; otherwise passed to brms::pp_check().
group	Character. Optional grouping variable for faceting. For non-multinomial models, passed to brms::pp_check(); when specified, the grouped variant of type (e.g., "dens_overlay_grouped") is auto-selected if available. For multinomial models, facets by the named predictor.
...	Additional arguments forwarded to brms::pp_check() (non-multinomial) or to brms::posterior_predict() (multinomial). For multinomial models, probs (numeric vector of length 2, default c(0.025, 0.975)) controls the credible interval. Both model types accept re_formula (e.g., re_formula = NA to predict at the population level, excluding random effects).

Details

For multinomial models, the plot mirrors the bayesplot ppc_bars style: observed proportions are shown as bars and posterior predictive medians with credible intervals are shown as point-ranges, using the bayesplot default colour scheme and theme.

Value

For multinomial models, a ggplot2 object. For other models, the result of brms::pp_check().

See Also

brms::pp_check()

bmm documentation built on March 30, 2026, 5:08 p.m.