[R, ggplot2] ggplot2, facet_grid, free scales?

Question

In the following example, how do I get the y-axis limits to scale according to the data in each panel?

mt <- ggplot(mtcars, aes(mpg, wt, colour = factor(cyl))) + geom_point() 

Neither of these will do it:

mt + facet_grid(. ~ cyl, scales="free")
mt + facet_grid(. ~ cyl, scales="free_y")

Answer 1

Perhaps it's because you have only one y axis, using your way. Did you try something like this?

mt + facet_grid(cyl ~ ., scales="free")