Odp: Problem with retrieving updated variables after attach()
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)) Is this what you are after?
There is also
as.data.frame(as.list(pos.to.env(2)))
or ...as.environment("mat")
I wouldn't recommend using <<- like that though; the consequences of
spelling mistakes on the LHS are a bit scary. If you must, consider
with(pos.to.env(2),{
id <- sample(100,5)
age <- rnorm(5,mean=30)
})
or better, modify before attach, using within() or transform().
O__ ---- Peter Dalgaard ?ster Farimagsgade 5, Entr.B c/ /'_ --- Dept. of Biostatistics PO Box 2099, 1014 Cph. K (*) \(*) -- University of Copenhagen Denmark Ph: (+45) 35327918 ~~~~~~~~~~ - (p.dalgaard at biostat.ku.dk) FAX: (+45) 35327907