Message-ID: <49917FD9.50908@idi.ntnu.no>
Date: 2009-02-10T13:23:37Z
From: Wacek Kusnierczyk
Subject: Odp: Problem with retrieving updated variables after attach()
In-Reply-To: <20090210205744.52bad6fe@berwin-nus1>
Berwin A Turlach wrote:
> G'day David,
>
> On Tue, 10 Feb 2009 13:23:50 +0100
> David Croll <david.croll at gmx.ch> wrote:
>
>
>> Well, I knew that attach() only creates a copy of the variables in
>> the search path.
>>
>> What I wanted to ask was how to *retrieve* that copy...
>>
>> > mat
>> id age
>> 1 NA NA
>> 2 NA NA
>> 3 NA NA
>> 4 NA NA
>> 5 NA NA
>>
>> > attach(mat)
>>
>> > id <<- sample(100,5)
>> > age <<- rnorm(5,mean=30)
>>
>> How can I make a new data frame out of the id and age that were
>> changed above?
>>
>
> R> new.df <- data.frame(id,age)
>
> Or, perhaps more automatic:
>
> R> new.df <- do.call(data.frame, sapply(ls(pos=2), as.name))
>
>
or perhaps:
new.df <- as.data.frame(mget(names(mat), as.environment(2)))
vQ