[R] getting the name of variables passed to a function

[Prof Brian Ripley]

I would start from match.call(expand.dots=TRUE) which has done the hard 
work for you.

On Fri, 27 Jul 2007, Horace Tso wrote:

> Folks,
>
> I've entered into an R programming territory I'm not very familiar with, 
> thus this probably very elementary question concerning the mechanic of a 
> function call.
>
> I want to know from within a function the name of the variables I pass 
> down. The function makes use of the "..." to allow for multiple unknown 
> arguments,
>
> myfun = function(...) { do something }
>
> In the body I put,
>
> {
> nm <- names(list(...))
> nm
> }
>
> When the function is called with two vectors x, and y
>
> myfun(x, y)
>
> It returns NULL. However, when the call made is,
>
>> myfun(x=x, y=y)
>
> The result is
> [1] "x" "y"
>
> Question : how do i get the names of the unknown variables without 
> explicitly saying x=x...
>
> Thanks in advance.
>
> Horace
>
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>

-- 
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)
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