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
Try
dots <- list(...)
if (length(dots) == 0) {
## do something
}
On Thu, Jul 16, 2009 at 6:46 AM, Thomas Roth (geb.
Kaliwe)<hamstersquats at web.de> 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
>
> ______________________________________________
> R-help at 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.
>
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
>
> ______________________________________________
> R-help at 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.
>
--
Dimitris Rizopoulos
Assistant Professor
Department of Biostatistics
Erasmus University Medical Center
Address: PO Box 2040, 3000 CA Rotterdam, the Netherlands
Tel: +31/(0)10/7043478
Fax: +31/(0)10/7043014
Thank you both. Thomas Dimitris Rizopoulos schrieb:> 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 >> >> ______________________________________________ >> R-help at 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. >> >