How to draw grid on top of one geom but not another

Question

I have a ggplot2 plot seen here

library(ggridges)
library(tidyverse)

ggplot(iris, aes(x = Sepal.Length, y = Species)) + 
  geom_rect(xmin = 4, xmax = 7, ymin = 1, ymax = 6,
            fill = '#d6d6d6') +
  geom_density_ridges() +
  theme_ridges()

How can I make it so that the grid is drawn on top of my geom_rect but not my geom_density_ridge? I have seen the ability to place the grid on top of all data referenced here

with + theme( panel.background = element_rect(fill = NA), panel.ontop = TRUE )

But what I really want is for it to be in-between the geoms

@RicardoSemiãoeCastro `iris` is a built-in data set in R – Allan Cameron Oct 29 '20 at 17:23 — Allan Cameron, Oct 29 '20 at 17:23

score 1 · Accepted Answer · answered Oct 29 '20 at 17:29

It isn't really possible to move the panel grid over some geoms but not others (at least not without rendering the ggplot and hacking the underlying grobs).

However, the obvious workaround is to make the grid with hline and vline geoms:

library(ggridges)
library(tidyverse)

ggplot(iris, aes(x = Sepal.Length, y = Species)) + 
  geom_rect(xmin = 4, xmax = 7, ymin = 1, ymax = 6,
            fill = '#d6d6d6') +
  geom_hline(aes(yintercept = Species), color = "gray70") +
  geom_vline(data = data.frame(Sepal.Length = 4:8),
                               aes(xintercept = Sepal.Length),
             color = "gray70") +
  geom_density_ridges() +
  theme_ridges()

How to draw grid on top of one geom but not another

1 Answers1