break/exit script

Question

I have a program that does some data analysis and is a few hundred lines long.

Very early on in the program, I want to do some quality control and if there is not enou

Answer 1

You could use the stopifnot() function if you want the program to produce an error:

foo <- function(x) {
    stopifnot(x > 500)
    # rest of program
}