R help - Jul 2011 - call a function with explicitly not setting an argument

Is there a way to call a function, and explicitly set an argument to 'not
specified'? My situation is the following. I have a function which passes on
most of its arguments to another function. The second function, myfun2,
serializes all arguments and is out of my control. 

myfun <- function(...){
  return(myfun2(...));
}

now, the value for arguments of myfun are stored in variables. Say I want to
call it with arguments 'foo' and 'bar', which are stored in
variables
'myfoo' and 'mybar'. So in my script I call

myfun(foo=myfoo, bar=mybar);

However, I also want to be able to call myfun2 without any arguments. Is
there any value that I can assign to myfoo and mybar, so that
myfun(foo=myfoo, bar=mybar); is identical to myfun();





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On Sat, Jul 23, 2011 at 6:31 AM, jeroen00ms <jeroen.ooms at stat.ucla.edu>
wrote:
> Is there a way to call a function, and explicitly set an argument to
'not
> specified'? My situation is the following. I have a function which
passes on
> most of its arguments to another function. The second function, myfun2,
> serializes all arguments and is out of my control.
>
> myfun <- function(...){
> ?return(myfun2(...));
> }
>
> now, the value for arguments of myfun are stored in variables. Say I want
to
> call it with arguments 'foo' and 'bar', which are stored in
variables
> 'myfoo' and 'mybar'. So in my script I call
>
> myfun(foo=myfoo, bar=mybar);
>
> However, I also want to be able to call myfun2 without any arguments. Is
> there any value that I can assign to myfoo and mybar, so that
> myfun(foo=myfoo, bar=mybar); is identical to myfun();
I am not aware of any (which is not to say there is not), but what
about catching ... between myfun and myfun2, and removing the
arguments you do not want passed on?  I had something like this in
mind:

myfun2 <- function(test, ...) {
  cat(missing(test), fill = TRUE)
  cat(..., fill = TRUE)
}

myfun <- function(...) {
  d <- list(...)
  index <- sapply(d, identical, y = "RemoveMe")
  d <- d[!index]
  do.call(myfun2, d)
}

myfun(foo = 1, test = "hi")
myfun(foo = 1, test = "RemoveMe")


Josh


>
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>
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>
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> Sent from the R help mailing list archive at Nabble.com.
>
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>


-- 
Joshua Wiley
Ph.D. Student, Health Psychology
University of California, Los Angeles
https://joshuawiley.com/