`stat_difference()` doesn't work with categorical values

[teunbrand]

The following works fine:

library(ggh4x)
#> Loading required package: ggplot2

df <- data.frame(
  x = c("A","B"),
  min = 1:2,
  max = 2:1
)

ggplot(df, aes(seq_along(x))) +
  stat_difference(aes(ymin = min, ymax = max))

This doesn't.

ggplot(df, aes(x)) +
  stat_difference(aes(ymin = min, ymax = max))

^{Created on 2021-03-26 by the reprex package (v1.0.0)}

[teunbrand]

This should now work:

library(ggh4x)
#> Loading required package: ggplot2

df <- data.frame(
  x = c("A","B"),
  min = 1:2,
  max = 2:1
)

ggplot(df, aes(x, group = 1)) +
  stat_difference(aes(ymin = min, ymax = max))

^{Created on 2021-04-10 by the reprex package (v1.0.0)}