Merge pull request #5115 from teunbrand/ecdf_scale_transform

`stat_ecdf()` responds to scale transform

Author: teunbrand

NEWS.md

@@ -1,13 +1,15 @@
 # ggplot2 (development version)
 
+* Renamed computed aesthetic in `stat_ecdf()` to `ecdf`, to prevent incorrect
+  scale transformations (@teunbrand, #5113 and #5112).
 * Fixed misbehaviour of `draw_key_boxplot()` and `draw_key_crossbar()` with 
   skewed key aspect ratio (@teunbrand, #5082).
 * `scale_*_binned()` handles zero-range limits more gracefully (@teunbrand, 
   #5066)
 * Binned scales are now compatible with `trans = "date"` and `trans = "time"` 
   (@teunbrand, #4217).
 * `ggsave()` warns when multiple `filename`s are given, and only writes to the
-  first file (@teunbrand, #5114).
+  first file (@teunbrand, #5114)
 * Fixed a regression in `geom_hex()` where aesthetics were replicated across 
   bins (@thomasp85, #5037 and #5044)
 * Fixed spurious warning when `weight` aesthetic was used in `stat_smooth()` 

R/stat-ecdf.r

@@ -21,7 +21,7 @@
 #' @param pad If `TRUE`, pad the ecdf with additional points (-Inf, 0)
 #'   and (Inf, 1)
 #' @eval rd_computed_vars(
-#'   y = "Cumulative density corresponding to `x`."
+#'   ecdf = "Cumulative density corresponding to `x`."
 #' )
 #' @export
 #' @examples
@@ -73,7 +73,7 @@ stat_ecdf <- function(mapping = NULL, data = NULL,
 StatEcdf <- ggproto("StatEcdf", Stat,
   required_aes = c("x|y"),
 
-  default_aes = aes(y = after_stat(y)),
+  default_aes = aes(x = after_stat(ecdf), y = after_stat(ecdf)),
 
   setup_params = function(self, data, params) {
     params$flipped_aes <- has_flipped_aes(data, params, main_is_orthogonal = FALSE, main_is_continuous = TRUE)
@@ -103,7 +103,7 @@ StatEcdf <- ggproto("StatEcdf", Stat,
 
     df_ecdf <- data_frame0(
       x = x,
-      y = data_ecdf,
+      ecdf = data_ecdf,
       .size = length(x)
     )
     df_ecdf$flipped_aes <- flipped_aes

man/stat_ecdf.Rd

@@ -15,3 +15,15 @@ test_that("stat_ecdf works in both directions", {
   expect_snapshot_error(ggplot_build(p))
 })
 
+# See #5113 and #5112
+test_that("stat_ecdf responds to axis transformations", {
+  n <- 4
+  answer <- c(seq(0, 1, length.out = n + 1), 1)
+  p <- ggplot(data_frame0(x = seq_len(n)), aes(x)) + stat_ecdf()
+
+  ld <- layer_data(p)
+  expect_equal(ld$y, answer)
+
+  ld <- layer_data(p + scale_y_sqrt())
+  expect_equal(ld$y, sqrt(answer))
+})