Fix the distance between the plotting area and x-axis label in plotnine / ggplot

Question

I want to fix/set (not increase) the distance between the plotting area and the x-axis label in plotnine/ggplot.

library(ggplot2)
ggplot(diamonds)
ggplot(diamonds) + geom_point(aes(x=carat, y=price, color=cut)) + geom_smooth(aes(x=carat, y=price, color=cut)) 

I want to fix the distance between the two red bars on . I would like to be able to have x-ticklabels that take up more space (rotated, larger font etc.) without affecting where the x-axis label is located relative to the plot. I have found many examples to adjust the spacing - but not manually set it.

Answer 1

This might be an R specific solution, I don't know how plotnine works under the hood. In R, the height of the x-axis label is determined dynamically by the dimensions of the text, and there is no convenient way of setting this manually (afaik).

Instead, one can edit the height of that row in the gtable and then plot the result.

library(ggplot2)
library(grid)

p <- ggplot(diamonds) + 
  geom_point(aes(x=carat, y=price, color=cut)) + 
  geom_smooth(aes(x=carat, y=price, color=cut)) 

# Convert plot to gtable
gt <- ggplotGrob(p)
#> `geom_smooth()` using method = 'gam' and formula 'y ~ s(x, bs = "cs")'
# Find row in gtable where the bottom axis is located
axis_row <- with(gt$layout, t[grep("axis-b", name)])
# Manually set the height of that row
gt$heights[axis_row] <- unit(2, "cm")

# Display new plot
grid.newpage(); grid.draw(gt)

^{Created on 2021-08-17 by the reprex package (v1.0.0)}