On Jan 9, 2013, at 1:00 PM, ivo welch wrote:
> mea culpa.
>
> f <- function(...) {
> ## parse out the arguments and then do something with them
> }
>
> ## all of these should result in the same actions
> f(2,3) ## interprets a to be first and b to be second
> f(a=2,b=3)
> f(b=3,a=2)
> f(data.frame(a=2,b=3))
> f(data.frame(b=3,a=1))
>
In the last two instances you are only passing a single object. I suppose you
could construct the argument list with
f <- function( a=NA, ...) { code}
But this works:
f <- function(a=NA, b=NA) if( !is.list(a) ) {print(a); cat("\n"); print(b) }
else{
with(a, {print(a); cat("\n");
print(b)} ) }
There is some concern for using with in functions so maybe you would want
access values with
a[["a"]] and a[["b"]]
Test output.
> f(2,3)
[1] 2
[1] 3
> f(a=2,b=3)
[1] 2
[1] 3
> f(b=3,a=2)
[1] 2
[1] 3
> f(data.frame(a=2,b=3))
[1] 2
[1] 3
> f(data.frame(b=3,a=1))
[1] 1
[1] 3
>
>
> On Tue, Jan 8, 2013 at 8:00 AM, David Winsemius <dwinsem...@comcast.net>
> wrote:
>>
>> On Jan 7, 2013, at 6:58 PM, ivo welch wrote:
>>
>>> hi david---can you give just a little more of an example? the
>>> function should work with call by order, call by name, and data frame
>>> whose columns are the names. /iaw
>>>
>>
>> It is I who should be expecting you to provide an example.
>>
>> -- David.
>>
David Winsemius
Alameda, CA, USA
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