[R] wildcards and removing variables

Prof Brian Ripley ripley at stats.ox.ac.uk
Mon Oct 10 17:01:43 CEST 2005


On Mon, 10 Oct 2005, Marc Schwartz (via MN) wrote:

> On Mon, 2005-10-10 at 10:37 -0400, Afshartous, David wrote:
>> 	All,
>>
>> 	Is there are a wildcard in R for varible names as in unix?  For example,
>>
>> 	rm(results*)
>>
>> 	to remove all variable or function names that begin w/ "results"?
>>
>> 	cheers,
>> 	Dave
>> 	ps - please respond directly to afshar at miami.edu
>
>
> See ?ls, which has a 'pattern' argument, enabling the use of Regex to
> define the objects to be listed and subsequently removed using rm().
>
> You can then use something like:
>
>  rm(list = ls(pattern = "\\bresults."))

One new feature of R-2.2.0 is glob2rx, which converts wildcards to regexps 
for you. E.g.

rm(list = ls(pattern = glob2rc("results*")))

(I think if does it a little better, as that trailing dot is not I think 
correct: result* matches result.)

-- 
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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