The following code use to work pre-version .9 of ggplot2. Is this not possible anymore?
df = data.frame(x = letters[1:26], y=abs(rnorm(26)))
ggplot(df, aes(x=x, y=y)) + geom_bar() + geom_vline(xintercept='m')
I get the following error:
Error in get(as.character(FUN), mode = "function", envir = envir) :
object ‘m’ of mode ‘function’ was not found
I don’t know (don’t remember) if your original used to work with old version of ggplot but you can use an another approach like this one :
Hope this help !!!