[19378] in s-news-athena
Re: [S] Repeating a Data Frame
daemon@ATHENA.MIT.EDU (Bill Venables)
Fri Oct 1 20:16:50 1999
Message-Id: <199910020008.KAA19236@snowy.nsw.cmis.CSIRO.AU>
To: "Humbolt, Allen" <HumboltA@kochind.com>
Cc: s-news@wubios.wustl.edu
In-Reply-To: Your message of "Fri, 01 Oct 1999 17:19:32 EST."
<8FE5933BB8DBD111803F00805F9F74BD025B851A@ictmail10.kochind.com>
Date: Sat, 02 Oct 1999 10:06:11 +1000
From: Bill Venables <William.Venables@cmis.CSIRO.AU>
Hi Allen,
How's tricks?
> I've got a dataframe I'll call "Dat" that I'd like to repeat 27 times.
> I want to do something like
> BigDat <- rbind(rep(Dat, 27))
> but that doesn't work like I want when Dat is a dataframe.
> It just creates the same number of rows with my columns repeated 27 times.
> I want BigDat to have the same number of columns with 27 times as many rows.
>
> Can someone show me how to do this?
I think it needs a loop. The simplest is certainly
BigDat <- NULL
for(i in 1:27) BigDat <- rbind(BigDat, Dat)
If 27 really is the number and you want to do this sort of thing
all the time you can slick things up just slightly by
BigDat <- Dat
for(i in 1:3) BigDat <- rbind(BigDat, BigDat, BigDat)
[think about it...]
You can hide the loop in various clever ways, such as
BigDat <- do.call("rbind", lapply(1:27, function(x) Dat))
but I'd be very surprised if you gained all that much...
Bill.
--
-----------------------------------------------------------------
Bill Venables, Statistician, CMIS Environmetrics Project.
Physical address: Postal address:
CSIRO Marine Laboratories, PO Box 120,
233 Middle St, Cleveland, Queensland Cleveland, Qld, 4163
AUSTRALIA AUSTRALIA
Telephone: +61 7 3826 7251 Email: Bill.Venables@cmis.csiro.au
Fax: +61 7 3826 7304
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