[R] New unique name
Prof Brian Ripley
ripley at stats.ox.ac.uk
Mon Apr 19 11:46:05 CEST 2004
On Mon, 19 Apr 2004, Erich Neuwirth wrote:
> In some languages there is a function
> which returns a new unique name (in the current environment).
> This is quite helpful when one has to do temporary assignments.
> I could not find such a function in R.
> Is there one?
Not that I know of. `In the current environment' is problematic, since R
has many environments and lexical scoping so different functions can have
different environments. It's better to pick your own:
ErichNeuwirth190404a looks unlikely to be used by anyone else!
basename(tempfile("ENeuwirth")) also looks like a good start.
Normally this is done within the body of a function, and all one needs to
do is to choose a symbol name not used in that function (although we do
see occasional problem with the use of `x' causing masking).
An alternative is to use a nested function for the computations, or to set
up a temporary environment (most conveniently via local()). (If perchance
you meant the local frame, then using local() is the R equivalent.)
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)
1 South Parks Road, +44 1865 272866 (PA)
Oxford OX1 3TG, UK Fax: +44 1865 272595
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