save an object by dynamicly created name

On Nov 1, 2009, at 10:16 PM, Henrik Bengtsson wrote:

path <- "data";
dir.create(path);

for (i in 1:10) {
?m <- i:5;
?filename <- sprintf("m%02d.Rbin", i);
?pathname <- file.path(path, filename);
?save(m, file=pathname);
}

That would result in each of the ten files containing an object with the
same ?name == "m". (Also on my system R data files have type Rdta.) So I
thought what was requested might have been a slight mod:

path <- "~/";
dir.create(path);

for (i in 1:10) {
?assign( paste("m", i, sep=""), ?i:5)
?filename <- sprintf("m%02d.Rdta", i)
?pathname <- file.path(path, filename)
?obj =get(paste("m", i, sep=""))
?save(obj, file=pathname)
}
Then a more convenient solution is to use saveObject() and
loadObject() of R.utils.  saveObject() does not save the name of the
object save.  If you want to save multiple objects, the wrap them up
in a list.  loadObject() does not assign variable, but instead return
them. Example:

library("R.utils");
x <- list(a=1,b=LETTERS,c=Sys.time());
saveObject(x, file="foo.Rbin");
y <- loadObject("foo.Rbin");
stopifnot(identical(x,y));

So, for the original example, I'd recommend:

library("R.utils");
path <- "data";
mkdirs(path);

for (i in 1:10) {
  m <- i:5;
  filename <- sprintf("m%02d.Rbin", i);
  saveObject(m, file=filename, path=path);
}

and loading the objects back as:

for (i in 1:10) {
  filename <- sprintf("m%02d.Rbin", i);
  m <- loadObject(filename, path=path);
  print(m);
}

/Henrik
--
David.

/H

On Sun, Nov 1, 2009 at 6:53 PM, jeffc <hcen at andrew.cmu.edu> wrote:
Hi,

I would like to save a few dynamically created objects to disk. The
following is the basic flow of the code segment

for(i = 1:10) {
?m = i:5
?save(m, file = ...) ## ???
}
To distinguish different objects to be saved, I would like to save m as
m1,
m2, m3 ..., to file /home/data/m1, /home/data/m2, home/data/m3, ...

I tried a couple of methods on translating between object names and
strings
(below) but couldn't get it to work.
https://stat.ethz.ch/pipermail/r-help/2008-November/178965.html
http://tolstoy.newcastle.edu.au/R/help/04/08/2673.html

Any suggestions would be appreciated.

thanks

Hao

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______________________________________________
R-help at 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.
David Winsemius, MD
Heritage Laboratories
West Hartford, CT

______________________________________________
R-help at 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.

save an object by dynamicly created name

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