Random-effect normal QQ plots for discounting models — plot

QQ plot of the estimated subject random-effect deviates against a normal reference – the standard check on the Gaussian random-effects assumption. Methods exist for the TMB indifference-point (fit_dd_tmb()) and choice (fit_dd_choice()) models. Bayesian fits are intentionally excluded; use brms::pp_check() and MCMC diagnostics there instead. The plotted deviates are shrunken (empirical-Bayes) estimates, so the normal reference is approximate.

Usage

# S3 method for class 'beezdiscounting_tmb'
plot_qq(object, which = NULL, ...)

# S3 method for class 'beezdiscounting_choice'
plot_qq(object, which = NULL, ...)

Arguments

object: A fitted beezdiscounting_tmb or beezdiscounting_choice model.
which: Optional character vector selecting random-effect terms to show.
...: Unused.

Value

A ggplot2::ggplot object.