thank you to both Adaikalavan and Patrick.
on the basis of Adaikalavan example this is an example that point out my problems. >log_raise=function(num, exp, base){return(log(num^exp,base))} I would like to have optional fields, so some settings to be default parameters; if I declare the function as above the operator must of course input all the variables. Finally I could fix as follow. > log_raise=function(num, exp=2, base=exp){return(log(num^exp,base))} thank you helps, cheers Claudio Patrick Burns ---------- Initial Header ----------- >From : "Adaikalavan Ramasamy" [EMAIL PROTECTED] To : "[EMAIL PROTECTED]" [EMAIL PROTECTED] Cc : "r-help" r-help@stat.math.ethz.ch Date : Sun, 20 May 2007 00:21:32 +0100 Subject : Re: [R] optional fields in function declarations > 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. > > > > > > > > ------------------------------------------------------ Leggi GRATIS le tue mail con il telefonino i-modeĀ di Wind http://i-mode.wind.it/ ______________________________________________ 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.