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
> >
> >
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> >
> >
> >
>
>
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