https://github.com/cran/bayestestR
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Tip revision: 6acd4f1707b182a2cbe2f4a4c2d4196571d36eb3 authored by Dominique Makowski on 05 December 2020, 08:30 UTC
version 0.8.0
Tip revision: 6acd4f1
describe_prior.R
#' Describe Priors
#'
#' Returns a summary of the priors used in the model.
#'
#' @param model A Bayesian model.
#' @param ... Currently not used.
#'
#' @examples
#' \dontrun{
#' library(bayestestR)
#'
#' # rstanarm models
#' # -----------------------------------------------
#' if (require("rstanarm")) {
#'   model <- rstanarm::stan_glm(mpg ~ wt + cyl, data = mtcars)
#'   describe_prior(model)
#' }
#'
#' # brms models
#' # -----------------------------------------------
#' if (require("brms")) {
#'   model <- brms::brm(mpg ~ wt + cyl, data = mtcars)
#'   describe_prior(model)
#' }
#'
#' # BayesFactor objects
#' # -----------------------------------------------
#' if (require("BayesFactor")) {
#'   bf <- ttestBF(x = rnorm(100, 1, 1))
#'   describe_prior(bf)
#' }
#' }
#' @importFrom insight get_priors
#' @export
describe_prior <- function(model, ...) {
  UseMethod("describe_prior")
}



#' @keywords internal
.describe_prior <- function(model, ...) {
  priors <- insight::get_priors(model, ...)

  # Format names
  names(priors)[-1] <- paste0("Prior_", names(priors)[-1])

  # If the prior scale has been adjusted, it is the actual scale that was used.
  if ("Prior_Adjusted_Scale" %in% names(priors)) {
    priors$Prior_Scale[!is.na(priors$Prior_Adjusted_Scale)] <- priors$Prior_Adjusted_Scale[!is.na(priors$Prior_Adjusted_Scale)]
    priors$Prior_Adjusted_Scale <- NULL
  }

  if ("Prior_Response" %in% names(priors)) {
    names(priors)[names(priors) == "Prior_Response"] <- "Response"
  }

  priors
}


#' @export
describe_prior.stanreg <- .describe_prior

#' @export
describe_prior.brmsfit <- .describe_prior

#' @export
describe_prior.bcplm <- .describe_prior

#' @export
describe_prior.mcmc.list <- function(model, ...) {
  NULL
}




#' @export
describe_prior.BFBayesFactor <- function(model, ...) {
  priors <- insight::get_priors(model)

  # Format names
  names(priors)[-1] <- paste0("Prior_", names(priors)[-1])

  priors
}
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