[R] Problem with data.frames

[Prof Brian Ripley]

On Mon, 4 Aug 2003, Simon Fear wrote:

> What I meant by "like library()" is that this function ensures that a
> library
> (or should I say package?) does not get loaded twice / duplicated in the
> search path. Of course attach() is not the same as library(). Nor is it
> the
> same as with() - I just thought it might be useful if the help pages
> pointed
> to each other. 

Yes. The strange thing to me is that with does not point to attach.
We'll add xrefs.

> Because I have programmed for years using attach() and
> detach() and only very recently discovered with() (which is nearly
> always
> what I want since I work mostly with scripts).
> 
> > So how can you tell if the data frame is on the search list
> 
> "my.dframe" %in% search() ?

That says if a data frame *of that name* is on the search list, and my 
point was that whereas packages are responably identified by name, data 
frames are not.  It's common to use DF tmp repeatedly.


-- 
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