Try this:

foo <- function(data, ...)
{
### here I want to check whether xlab was passed with the ... arguments
### or if the ... arguments did not contain an xlab argument
args <- list(...)
return(ifelse("xlab" %in% names(args), "Exists", "Missing"))
}

On Thu, Dec 11, 2008 at 4:22 PM, Mark Heckmann <mark.heckmann@gmx.de> wrote:

> Hi,
>
> How can I check if a certain ... argument has been passed on to my
> user-defined function or not?
>
> foo <- function(data, ...)
> {
> ### here I want to check whether xlab was passed with the ... arguments
> ### or if the ... arguments did not contain an xlab argument
> }
>
> I tried  missing(xlab)  , exists(xlab) and several other things but did not
> find a solution.
>
> TIA,
> Mark
>
> ______________________________________________
> R-help@r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
> http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>



-- 
Henrique Dallazuanna
Curitiba-Paraná-Brasil
25° 25' 40" S 49° 16' 22" O

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