[R] how to check if ... is empty

[Dimitris Rizopoulos]

one way is:

test <- function(x, y, ...) {
     dots <- list(...)
     if (length(dots)) cat("\nnon-empty\n") else cat("\nempty\n")
}

test(1, 1)
test(1, 1, 1)


I hope it helps.

Best,
Dimitris


Thomas Roth (geb. Kaliwe) wrote:
> Hi,
> 
> I was wondering what would be the best way to check if the three dots 
> argument contains any arguments (i.e. does ... contain any arguments or 
> not? )
> 
> #Example
> 
> test = function(x,y, ...)
> {
>    #Wanted R-Code
>    # if(empty(...))
>    #    do some calculation
> 
> 
>    plot(x,y,...)
> 
> }
> 
> Thanks
> 
> Thomas Roth
> 
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-- 
Dimitris Rizopoulos
Assistant Professor
Department of Biostatistics
Erasmus University Medical Center

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