Add preserve argument to position_jitterdodge()

[luckybarrel54-sudo]

In situations when I want to plot stacked box plot with scatter plot of individual data points on top of it, but the dataset contains some missing data, while I can use the position_dodge(preserve = "single") argument to ensure the bars are not combined, it is not possible to do so with the scatter plot of data points, since position_jitterdodge() does not have the "preserve" argument.

I would like to be able to add the preserve argument to position_jitterdodge()

ggplot(data, aes(x = Var1, y = Var2, fill = Var3) +
stat_summary(geom = "bar", fun = "mean", show.legend = T, position = position_dodge(preserve = "single")) +
stat_summary(geom = "errorbar", fun.data = "mean_sdl", fun.args = list(mult = 1),
width = 0.3, position = position_dodge(width = 1, preserve = "single")) +
geom_point(show.legend = F, position = position_jitterdodge(jitter.width = 0.3, dodge.width = 1, preserve = "single"))

[teunbrand]

This is just filling in the data to ensure that we have a working reprex.
Is this the problem that you're seeing, i.e. the points not lining up with the bars?

library(ggplot2)

ggplot(penguins, aes(species, bill_len, fill = island)) +
  stat_summary(
    geom = "bar",
    fun = "mean",
    show.legend = T,
    position = position_dodge(preserve = "single")
  ) +
  stat_summary(
    geom = "errorbar",
    fun.data = "mean_sdl",
    fun.args = list(mult = 1),
    width = 0.3,
    position = position_dodge(width = 1, preserve = "single")
  ) +
  geom_point(
    show.legend = F,
    position = position_jitterdodge(jitter.width = 0.3, dodge.width = 1)
  )
#> Warning: Removed 2 rows containing non-finite outside the scale range
#> (`stat_summary()`).
#> Removed 2 rows containing non-finite outside the scale range
#> (`stat_summary()`).
#> Warning: Removed 2 rows containing missing values or values outside the scale range
#> (`geom_point()`).

^{Created on 2025-09-02 with reprex v2.1.1}

[luckybarrel54-sudo]

Yes, thank you, that is the issue. Very nice!

[luckybarrel54-sudo]

On an unrelated note, I have to add, since I usually have a stack of two bars next to each other and I have never had the need to make a stack of three before, in the above plot, in Chinstrap, the green bar is plotted in the place of the red bar. So the position is not maintained according to the order of island (as seen in Adelie)? That's strange isn't it?

[teunbrand]

Yeah agreed, but that is covered already in the upcoming version.
Any fix for position_jitterdodge() should probably also follow in these footsteps.

ggplot2/NEWS.md

Lines 177 to 179 in bed8e32

	* Position adjustments can now have auxiliary aesthetics (@teunbrand).
	* `position_nudge()` gains `nudge_x` and `nudge_y` aesthetics (#3026, #5445).
	* `position_dodge()` gains `order` aesthetic (#3022, #3345)