From gregor.gorjanc at gmail.com  Sun Jul  2 03:00:33 2006
From: gregor.gorjanc at gmail.com (Gregor Gorjanc)
Date: Sun, 02 Jul 2006 03:00:33 +0200
Subject: [Rd] Test for argument in ...
Message-ID: <44A71AB1.4000804@bfro.uni-lj.si>

Hello!

Say I have a function foo1, which has argument ... to pass various
arguments to foo2 i.e.

foo1 <- function(x, ...)
{
  foo2(x, ...)
}

Say that foo2 accepts argument arg1 and I would like to do the following:
- if foo1 is called as foo1(x) then I would like to assign some value to
arg1 inside foo1 before calling foo2

arg1 <- "some value"
foo2(x, arg1=arg1)

- if foo1 is called foo1(arg1="some other value") do not assign some
value to arg1 and call foo2

foo2(arg1=arg1)

However, I am not able to do this since I do not know how to test/check
if arg1 was given in foo1. Is it possible to test whether some argument
was passed in "..." i.e. something like

foo1 <- function(x, ...)
{
  if(testForArgumentInThreeDots(arg1)) arg1 <- "some value"
  foo2(x, arg1=arg1, ...)
}

Thanks!

-- 
Lep pozdrav / With regards,
    Gregor Gorjanc

----------------------------------------------------------------------
University of Ljubljana     PhD student
Biotechnical Faculty
Zootechnical Department     URI: http://www.bfro.uni-lj.si/MR/ggorjan
Groblje 3                   mail: gregor.gorjanc <at> bfro.uni-lj.si

SI-1230 Domzale             tel: +386 (0)1 72 17 861
Slovenia, Europe            fax: +386 (0)1 72 17 888

----------------------------------------------------------------------
"One must learn by doing the thing; for though you think you know it,
 you have no certainty until you try." Sophocles ~ 450 B.C.



[Rd] Test for argument in ...
Gregor Gorjanc