On 12-12-11 12:42 AM, Worik R wrote:
You may find it more reliable to define an environment in which you
will be storing your data (perhaps globalenv(), perhaps something created
by new.env()) and then testing for existence of a dataset by a given name
in that environment.
I did that.
PAIR.ENV <- new.env()
....
get("USDCHF", env=PAIR.ENV)
returns trhe USDCHF defined in timeSeries
This is very hard!
I think if you had followed my advice (reading up on scoping) you
wouldn't find it so hard. new.env() creates a new environment whose
parent (or enclosure) is globalenv(). So when you do a search in
PAIR.ENV, you'll search there first, then in globalenv(), then in its
parent, etc.
If you don't want this to happen, don't set globalenv() as the parent.
emptyenv() is likely what you want instead:
PAIR.ENV <- new.env(parent=emptyenv())
means that only the objects you put there will be found.
Duncan Murdoch
Worik
Bill Dunlap
Spotfire, TIBCO Software
wdunlap tibco.com
-----Original Message-----
From: r-help-boun...@r-project.org [mailto:r-help-boun...@r-project.org]
On Behalf
Of Worik R
Sent: Monday, December 10, 2012 5:47 PM
To: Duncan Murdoch
Cc: r-help
Subject: Re: [R] Removing named objects using rm(..)
On Tue, Dec 11, 2012 at 2:27 PM, Duncan Murdoch
<murdoch.dun...@gmail.com>wrote:
On 12-12-10 7:33 PM, Worik R wrote:
Let me restate my question.
Is there a straightforward way of ensuring I can use the variable name
USDCHF?
You can use any legal variable name. The only risk is that you will
overwrite some other variable that you created. You can't overwrite
variables from packages. (You might mask them, but they are still
accessible using the :: notation. E.g. after you set
USDCHF <- NULL
Exactly. I got around this by assigning NULL to the variable names that
I
would have deleted. Then instead of testing for existence I tested for
NULL.
you can still access the one in timeSeries using
timeSeries::USDCHF
Christ. That is what I wanted to delete. I read the scoping section of
R-Lang (again) and nothing I could see prepared me for the shock of...
library(timeSeries)
nrow(USDCHF)
[1] 62496
rm(USDCHF)
Warning message:
In rm(USDCHF) : object 'USDCHF' not found
nrow(USDCHF)
[1] 62496
The message from rm was that USDCHF did not exist. But I can still
access
its properties with nrow.
This is very broken. I would not have believed I would see that in the
21st century with a modern language. (Oh wait, there is Javascript and
PHP, so in comparison R is not that broken)
I am not new to R, I have been (mis)using it for 5 years. I love aspects
of R, but this and a few other things (lack of debugging support and
ignoring the "principle of least surprise" are two biggies) are very
frustrating. Without debugging support or more help from the compiler
(like a "cannot rm EURCHF" message instead of a lie) R causes as many
problems as it solves.
Sigh. Thanks for the help.
Worik
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and provide commented, minimal, self-contained, reproducible code.
______________________________________________
R-help@r-project.org mailing list
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PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
