Revert stat_function -> geom_function change, keep override.aes fix

As requested: stat_function isn't deprecated, and switching to
geom_function could break backwards compatibility for users passing
geom via overlay_function(...). Only the size -> linewidth fix in
override.aes remains.

Author: ishaan-arora-1

R/bayesplot-helpers.R

@@ -21,7 +21,7 @@
 #'   [ggplot2::element_line()].
 #'
 #'   For `overlay_function`, `...` is passed to
-#'   [ggplot2::geom_function()].
+#'   [ggplot2::stat_function()].
 #'
 #' @return
 #' A **ggplot2** layer or [ggplot2::theme()] object that can be
@@ -91,7 +91,7 @@
 #' }
 #'
 #' \subsection{Superimpose a function on an existing plot}{
-#' * `overlay_function()` is a simple wrapper for [ggplot2::geom_function()] but
+#' * `overlay_function()` is a simple wrapper for [ggplot2::stat_function()] but
 #'   with the `inherit.aes` argument fixed to `FALSE`. Fixing `inherit.aes=FALSE`
 #'   will avoid potential errors due to the [ggplot2::aes()]thetic mapping used by
 #'   certain **bayesplot** plotting functions.
@@ -476,7 +476,7 @@ grid_lines_y <- function(color = "gray50", linewidth = 0.2) {
 #' @rdname bayesplot-helpers
 #' @export
 overlay_function <- function(...) {
-  geom_function(..., inherit.aes = FALSE)
+  stat_function(..., inherit.aes = FALSE)
 }
 
 

man/bayesplot-helpers.Rd

@@ -180,8 +180,9 @@ test_that("yaxis_ticks returns correct theme object", {
 
 # overlay functions -------------------------------------------------------
 test_that("overlay_function returns the correct object", {
+  expect_error(overlay_function(), 'argument "fun" is missing')
   a <- overlay_function(fun = "dnorm")
-  b <- geom_function(fun = "dnorm", inherit.aes = FALSE)
+  b <- stat_function(fun = "dnorm", inherit.aes = FALSE)
   a$constructor <- b$constructor <- NULL
   expect_equal(a, b, ignore_function_env = TRUE)
 })