[R] S. function calculating x +- y

[Sascha Vieweg]

Hello, I am looking for an elegant one-liner for the following 
operation:

x <- rnorm(10)
y <- runif(10)
c(mean(x)-mean(y), mean(x)+mean(y))

I thought about

apply(data.frame(x, y), 2, mean)

but I don't know how to apply the +- operation on the result of 
apply. Thanks, *S*

-- 
Sascha Vieweg, saschaview at gmail.com