Using facet tags and strip labels together in ggplot2

Question

I\'d like to create a figure using ggplot2\'s facet_grid, like below:

# Load ggplot2 librar         


        

Answer 1

This can be done using only geom_text() :

data_text <- data.frame(
  cyl   = c(4, 6, 8, 4, 6, 8, 4, 6, 8),
  gear  = c(3, 3, 3, 4, 4, 4, 5, 5, 5)
  label = c('(a)', '(b)', '(c)', '(d)', '(e)', '(f)', '(g)', '(h)', '(i)')
)

ggplot(mtcars, aes(mpg, wt)) +
geom_point() +
facet_grid(gear ~ cyl) +
geom_text(data=data_text, aes(x=12, y=5, label=label), fontface='bold', size=4)