Annotating text on individual facet in ggplot2 using geom_text

Question

With the following code, I obtain text on each facet but the text is superimposed: "X1" and "X2" are superimposed on each facet. Where is the problem in my code?

R code:

new_df <- data.frame(f = as.factor(rep(1:2, 15)), x = rnorm(30), y = runif(30))
g <- ggplot(data = new_df, aes(x = x, y = y)) + geom_point() 
g <- g + facet_grid(. ~ f)
g
label_graph <- data.frame(label = c("X1", "X2"))

g <- g + geom_text(data = label_graph,
                    mapping = aes(x = Inf, y = -Inf, label = label),
                    hjust = 1.1, vjust = -1.1)
g

Answer 1

Is it an option for you to label the facet headers directly instead of labelling the bottom corners? Your example suggests that may be a better solution. If that works for your actual use case, you may simply change your f column directly by pasting the X , and you get:

new_df <- data.frame(f = as.factor(paste0("X", rep(1:2, 15))), x = rnorm(30), y = runif(30))
g <- ggplot(data = new_df, aes(x = x, y = y)) + geom_point() 
g <- g + facet_grid(. ~ f)
g

Answer 2

you need to add the column f to your label_graph, this way once the facet is applied, the labels are on the designated facet

new_df <- data.frame(f = as.factor(rep(1:2, 15)), x = rnorm(30), y = runif(30))
g <- ggplot(data = new_df, aes(x = x, y = y)) + geom_point() 
g <- g + facet_grid(. ~ f)
label_graph <- data.frame(label = c("X1", "X2"),f=factor(1:2))

g <- g + geom_text(data = label_graph,
                    mapping = aes(x = Inf, y = -Inf, label = label),
                    hjust = 1.1, vjust = -1.1)
g

Answer 3

Can you just add the labels to your original data?

new_df <- data.frame(f = as.factor(rep(1:2, 15)), x = rnorm(30), y = runif(30), label = c("X1","X2"))
g <- ggplot(data = new_df, aes(x = x, y = y)) + geom_point() 
g <- g + facet_grid(. ~ f)
g <- g+ geom_text(mapping = aes(x = Inf, y = -Inf, label = label),
               hjust = 1.1, vjust = -1.1)
g