----- Original Message -----
From: David Winsemius
Sent: 07/06/12 05:32 PM
To: knallgrau at gmx.com
Subject: Re: [R] automatic completion of object names
On Jul 6, 2012, at 9:36 AM, knallgrau at gmx.com wrote:
Hello there,
I just upgraded to R 2.15 (from R 2.12) on a Windows XP machine and
noticed some puzzling behaviour (that in my opinion did not exist in
R 2.12).
It is possible now to call objects without spelling out the full
object name. R now seems to use that (unique) object which shares
the same beginning of the called object, even though the originally
called object might not even exist.
This is quite awkwardly described, but perhaps you know what I'm
talking about?
Let's say I'm using the Mroz data supplied with the car package:
require(car)
data(Mroz)
there is no variable called "w" in that dataframe, but calling
summary(Mroz$w) #### Mroz$w does not exist
does not return any error but instead gives the same result as
summary(Mroz$wc) ##### exists in Mroz
I find this behaviour *very* undesirable. Is there any way to switch
it off?
It has always been the case. See the ?Extract page. The controlling
sentence is here>
" x$name is equivalent to x[["name", exact = FALSE]]. Also, the
partial matching behavior of[[ can be controlled using the exact
argument."
(I'm using R2.14.2 ... further evidence this is not new in 2.15.x)
?> summary(Mroz$w)
?no yes
541 212
--
David Winsemius, MD
West Hartford, CT