On 5/16/2011 1:43 AM, Martin Maechler wrote:
SpG> Might it be feasible to add, "See Also: missing"
SpG> to the help page for "exists"?
SpG> Currently, one can spend hours studying the help
SpG> page for "exists" without getting a clue to the answer
SpG> to the post copied below.
Yes. I've added such a link now...
though quite disillusioned with a very vague hope that useRs
would read the help page so thoroughly ...
Martin Maechler, ETH Zurich
Hi, Martin: Thanks much. I mentioned this because I have looked in
"See Also" for that kind of thing in the past. Of course, I may be the
only person who does this, so this change might not help anyone else.
Best Wishes, Spencer
SpG> Thanks, Spencer
SpG> On 5/14/2011 3:30 AM, David Winsemius wrote:
>>
>> On May 14, 2011, at 3:30 AM, utkarshsinghal wrote:
>>
>>>
Hi all,
I want to define a function such that one of its argument if passed
do one
thing and if not passed do the second thing.
?missing
So basically, I have to check
whether the argument is passed or not inside the function. I am
trying to
use 'exists' function to do this.
f = function(a,b){exists("b")}
f(a=3, b=4)
[1] TRUE
This is working as expected.
But if I do the following:
f(a=3)
[1] TRUE
Can anybody explain why this function is returning TRUE here.
--
Many thanks,
Utkarsh
...
David Winsemius, MD
West Hartford, CT
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