The x_axis text margin behavior when scale_x_discrete(position = "top")

[abiyug]

When patching parallel ggplot plots with the x axis text position set to the 'top', the text jumps up. This behavior doesn't happen when position is set to the "bottom".

Here is the Reprex:

library(tidyverse)
library(tidyr)
library(patchwork)

df <- mtcars %>% 
  select(mpg:carb) %>% 
  scale() %>%           
  as.data.frame() %>%
  cbind(rown = rownames(mtcars)) %>% 
  pivot_longer(mpg:carb, names_to = "car_model", 
                      values_to = "value")

gg_heat <-
ggplot(df, aes(y = rown, x = car_model, fill = value)) +
        geom_tile(color = "white", size = .6) + 
        scale_fill_gradient(low = "white",high = "red") +
        scale_x_discrete(position = "top") +
        theme_bw()  +
        geom_text(aes(label = round(value, 2)), 
                     colour = "black",
                     size = 3,
                     fontface = "bold")
gg_line <-
ggplot(mtcars, aes(wt, mpg)) + 
  geom_line() + 
  facet_wrap(~ am)
  
gg_line | gg_heat

[abiyug]

Any update?

[thomasp85]

this is because you are merging it with a faceted plot. axes are aligned between plots which means that if a plot has facet strips in between it will move up the axes of non-faceted plots

[abiyug]

I see. So is this as designed or will you look into put a fix for merging fcated cases?

[thomasp85]

It is unlikely to change, though I will not rule it out completely. When it comes to these edge cases patchwork will always err to the side of simplicity and consistency rather than complicating the API

[abiyug]

Don't rule it out. Thanks for responding.