Can you provide an simple example of what you want the function to do? Generally, I set some value in the default.
raise <- function(x, power=1){ return( x^power ) } > raise(5) [1] 5 > raise(5,3) [1] 125 Or you can do the same but in a slightly unclear manner. raise <- function(x, power){ if(missing(power)) power <- 1 return( x^power ) } I prefer the former. Regards, Adai [EMAIL PROTECTED] wrote: > Dear R users, > > I need to create a set of function to solve some tasks. I want to leave the > operator to decide whether uses default parameters or change it; so the > functions may have some optional fields. I tied to use the function > missing(), but it will work properly only if the optional field is decleared > at last in the function. > Can you give me some suggestion an some reference? > > thank you. > > > Claudio > > > ------------------------------------------------------ > Passa a Infostrada. ADSL e Telefono senza limiti e senza canone Telecom > http://click.libero.it/infostrada > > ______________________________________________ > R-help@stat.math.ethz.ch 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. > > > ______________________________________________ R-help@stat.math.ethz.ch 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.