Hi all,

I am reading books and tutorials about R.

I don't understand the following:

plot(salary~rank, data=salary)
plot(Ozone~date, data=airquality)

I don't understand what does "~" here, and how can plot() have a input
argument called "data"... I have looked it up in "plot"'s help but I could
not find about argument "data".

Could you please help me?

Thank you!

	[[alternative HTML version deleted]]


