`layer (layout)` does not work with `facet_wrap` when used on integer vectors

[Breeze-Hu]

Hi!

When experimenting with some of the new features introduced in version 4.0 and later, I encountered an unexpected behavior. According to the ggplot2 documentation, when the layer (layout) parameter is used in conjunction with facet_wrap, both integer vectors and the ‘fixed’ argument are valid.
https://ggplot2.tidyverse.org/reference/facet_wrap.html#:~:text=Layer%20layout,across%20every%20panel.

Layer layout
The layer(layout) argument in context of facet_wrap() can take the following values:

• NULL (default) to use the faceting variables to assign panels.
• An integer vector to include selected panels. Panel numbers not included in the integer vector are excluded.
• "fixed" to repeat data across every panel.

However, based on the results, it appears that the integer values do not seem to have any effect on the panel markers.

library(ggplot2)
ggplot(mpg, aes(displ, hwy)) +
  geom_point(layout = 'fixed',colour = "grey", alpha = 0.3) +
  geom_point()+
  facet_wrap(vars(class), axes = "all", axis.labels = "all_y" )

ggplot(mpg, aes(displ, hwy)) +
  geom_point(layout = c(1,2,3),colour = "grey", alpha = 0.3) +
  geom_point()+
  facet_wrap(vars(class), axes = "all", axis.labels = "all_y" )

^{Created on 2026-07-28 with reprex v2.1.1}

Not sure if it's because I'm using it wrong, or if this is a bug? If it's the former, could you please tell me the correct way to use it?

All the best,
Hu

[teunbrand]

Hi Hu,

The points in the layout layer were hidden behind the points in the non-layout layer.
I think this behaviour is how it should work: you select points to display in panels 1, 2 and 3.
Does that run counter to your intuition?

library(ggplot2)

ggplot(mpg, aes(displ, hwy)) +
  geom_point(layout = c(1,2,3),colour = "grey") +
  facet_wrap(vars(class), axes = "all", axis.labels = "all_y")

^{Created on 2026-07-28 with reprex v2.1.1}

[Breeze-Hu]

Oh, so it’s similar to the process of selecting a data subset.

Does that run counter to your intuition?

I thought it was more like ‘fixed’ where all the data serves as the background (as point) but is only displayed on the panel we specify.
It does seem like I misunderstood.

Is it possible to implement my previous misunderstanding as a feature? Although I don’t know of any use cases for it right now.🤣

Thanks for your reply！

[Breeze-Hu]

I tested whether annotation support this approach and found that while it works for a single panel, it throws an error when used with integer vectors.

library(ggplot2)

ggplot(mpg, aes(displ, hwy)) +
  annotate(colour = "grey", geom = 'point',x = mpg$displ, y = mpg$hwy, layout = 1) +
  facet_wrap(vars(class), axes = "all", axis.labels = "all_y")

ggplot(mpg, aes(displ, hwy)) +
  annotate(colour = "grey", geom = 'point',x = mpg$displ, y = mpg$hwy, layout = c(1,2,3)) +
  facet_wrap(vars(class), axes = "all", axis.labels = "all_y")
#> Error in `annotate()`:
#> ! Unequal parameter lengths: x (234), y (234), and layout (3)

^{Created on 2026-07-28 with reprex v2.1.1}