vertical lines as separator between categorical groups in nested axis

[Johannes Werner]

First example from: https://teunbrand.github.io/ggh4x/reference/guide_axis_nested.html

# The defaults are suited for interaction variables
ggplot(mpg, aes(interaction(cyl, class), hwy)) +
  geom_boxplot() +
  scale_x_discrete(guide = "axis_nested")

Is it possible for clearer separation to add vertical lines between each group of the x axis?

Second, unrelated question: How can I show all cylinders for each car class? (i.e. can I show the values 4, 5, 6 and 8 for each car class without adding dummy data to the data frame)

Thank you!

[Teun van den Brand]

Hi there,

Is it possible for clearer separation to add vertical lines between each group of the x axis?

No, only horizontal indicators are possible. I don't plan on honouring any feature requests for guides at the moment, because I'm developing a separate package for this.

Second, unrelated question: How can I show all cylinders for each car class? (i.e. can I show the values 4, 5, 6 and 8 for each car class without adding dummy data to the data frame)

You can use drop = FALSE in the scale if you use interaction() in the aesthetic. Otherwise, you might have to set the scale's limits/breaks manually.

[Johannes Werner]

Thanks for letting me know and an answer for my second question. If you don't mind, what is the package name? Or is it not public (yet)?

[Teun van den Brand]

You can find the package here, but it certainly won't work without the development version of ggplot2.