Plot a function with ggplot, equivalent of curve()

Question

Is there an equivalent method for plotting functions using ggplot to the curve() command employed in base graphics? I guess that the alternative wo

Answer 1

The data.frame example above works well, and it makes grid lines. The qplot example doesn't work in ggplot2 2.2.0 for the reasons given.

You can also use the "curve" function in ggplot2 2.2.0, but it does not automatically make grid lines or background color. For example:

curve(cos(x), from= 0, to= pi/2).  

The "ggplot(data.frame(... ) method gives the full impressive range of ggplot2's formatting options. I like it.