Annotating text on individual facet in ggplot2

Question

I want to annotate some text on the last facet of the plot with the following code:

library(ggplot2)

p <- ggplot(mtcars, aes(mpg, wt)) + geom_point()

p <- p + facet_grid(. ~ cyl)

p <- p + annotate("text", label = "Test", size = 4, x = 15, y = 5)

print(p)

But this code annotates the text on every facet. I would highly appreciate if you guide me on how to get the annotated text on only one facet. Thanks in advance.

Answer 1

To annotate text on the last facet, add the following to your code:

text_ann <- data.frame(mpg = 15,wt = 5,lab = "Text",

                       cyl = factor(8,levels = c("4","6","8")))

p + geom_text(data = ann_text,label = "Text")

i.e.,

library(ggplot2)

ggplot(mtcars, aes(mpg, wt)) + geom_point()

p + facet_grid(. ~ cyl)

ann_text <- data.frame(mpg = 15,wt = 5,lab = "Text",

                       cyl = factor(8,levels = c("4","6","8")))

p + geom_text(data = ann_text,label = "Text")

Output: