Individual text box with Greek letter on each `facet

I need to fill $\lambda$ = x (6 values of x) on each of the 6 facet_grid panels

ggplot(mtcars, aes(mpg, wt))  
  geom_point()  
  facet_grid(am ~ cyl)  
  theme(panel.spacing = unit(1, "lines"))  
  annotate("text", label = c("\u03BB = 1", "\u03BB = 2", "\u03BB = 0.1", "\u03BB = 2.2", "\u03BB = 1.5", "\u03BB = 5") , size = 4, x = 30, y = 5)

I've modified the solutions here

CodePudding user response：

One option to achieve your desired result would be to add the labels via a geom_text and a data.frame of labels like so:

library(ggplot2)

df_label <- data.frame(
  label = c("\u03BB = 1", "\u03BB = 2", "\u03BB = 0.1", "\u03BB = 2.2", "\u03BB = 1.5", "\u03BB = 5"),
  am = rep(0:1, each = 3),
  cyl = rep(c(4, 6, 8), 2)
)

ggplot(mtcars, aes(mpg, wt))  
  geom_point()  
  geom_text(data = df_label, aes(label = label), size = 4, x = 30, y = 5)  
  facet_grid(am ~ cyl)  
  theme(panel.spacing = unit(1, "lines"))