[R] How do you exit a function in R?

[Roland Rau]

Hi

Bill Cunliffe wrote:
> For example, based on a certain condition, I may want to exit my code early:
> 
>  
> 
>             # Are there the same number of assets in "prices" and
> "positions"?
> 
>             if (nAssetPositions != nAssetPrices) {
> 
>                         cat("Different number of assets! \n\n")
> 
>                         <exit function>
> 
>             }
I think the easiest thing to use is the 'stopifnot()' function.
afunction <- function(myinput) {
	stopifnot(is.numeric(myinput))
	return(myinput * 2)
}

Alternatively, you can also do:

afunction2 <- function(myinput) {
	if (!is.numeric(myinput)) stop("Input not numeric")
	return(myinput * 2)
}

 > afunction("roland")
Error: is.numeric(myinput) is not TRUE
 > afunction2("roland")
Error in afunction2("roland") : Input not numeric
 > afunction2(123)
[1] 246
 > afunction(123)
[1] 246
 >


I hope this helps,
Roland