Error when all data is outside limits of continuous scale

[wch]

This is from the examples:

# OK
qplot(mpg, wt, data=mtcars) + ylim(0, 10)

# All data is outside y limits - Error
qplot(mpg, wt, data=mtcars) + ylim(10, 20)
# Error: Discrete value supplied to continuous scale

[hadley]

I think this should be simple fix: make censor return NA_real_ instead of NA (which is logical, and hence counted as discrete). Even better you should return an NA of the same type as x - but I don't know an easy way of doing that.