R help - Jan 2006 - Passing variable arguments to functions

Hi,

Is there another  way to pass arguments via a vector to arbitrary functions
as in the following code example without using a series of if else
statements?

f <- test(func, x, parms, fargs1, fargs2, ...)
{
   # parms is a vector of parameters to func.
   #  ... is for use by f, not by func.
   n <- length(parms)
   if (n == 0)         y <- func(x)
  else if (n == 1)   y <- func(x, parms[1])
  else if (n == 2)   y <- func(x, parms[1], parms[2])

 # remaining body of f follows.
}

Regards,

Ernie

	[[alternative HTML version deleted]]

?do.call is a good place to start.  If parms is a vector, then

y <- do.call(func, as.list(parms))

should do the job.  (And if parms is a list, your code probably does not 
do what you want.)

For such ideas, see `S Programming' (referenced in the FAQ).


On Fri, 20 Jan 2006, Ernesto Adorio wrote:
> Hi,
>
> Is there another  way to pass arguments via a vector to arbitrary functions
> as in the following code example without using a series of if else
> statements?
>
> f <- test(func, x, parms, fargs1, fargs2, ...)
> {
>   # parms is a vector of parameters to func.
>   #  ... is for use by f, not by func.
>   n <- length(parms)
>   if (n == 0)         y <- func(x)
>  else if (n == 1)   y <- func(x, parms[1])
>  else if (n == 2)   y <- func(x, parms[1], parms[2])
>
> # remaining body of f follows.
> }
>
> Regards,
>
> Ernie
>
> 	[[alternative HTML version deleted]]
>
> ______________________________________________
> R-help at 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
>
-- 
Brian D. Ripley,                  ripley at stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford,             Tel:  +44 1865 272861 (self)
1 South Parks Road,                     +44 1865 272866 (PA)
Oxford OX1 3TG, UK                Fax:  +44 1865 272595