geom_boxplot with continuous x and without group aesthetics

[krlmlr]

d <- data.frame(x=rep(1:10, 100), y=runif(1000))
ggplot(d) + geom_boxplot(aes(x=x, y=y))

will happily produce a single box, while the intention is probably to produce the output of this code:

d <- data.frame(x=rep(1:10, 100), y=runif(1000))
ggplot(d) + geom_boxplot(aes(x=x, y=y, group=x))

Would a warning be appropriate here -- if x is continuous and the group aesthetics is missing?

[hadley]

Maaaaybe, but I like that there's currently one unifying principle for grouping (i.e. all discrete variable for a group). But if you feel strongly about, I'd review a PR to add a warning.