R help - Jul 2012 - selecting a subset of files to be processed

Dear R People:

I am using a Linux system in which I have about 3000 files.

I would like to randomly select about 45 of those files to be processed in R.

Could I make the selection in R or should I do it in Linux, please?

This is with R-2.15.1.

Thanks,
erin


-- 
Erin Hodgess
Associate Professor
Department of Computer and Mathematical Sciences
University of Houston - Downtown
mailto: erinm.hodgess at gmail.com

Hi Erin,

It is not difficult to imagine doing it either in R or via the shell.
If they are all in the same directory, I would tend towards R, just
because you can easily set the seed and keep that information so you
can reproduce your random selection.

If the wd is in the directory with the files, from R just:

set.seed(10)
toprocess <- sample(list.files(), size = 45)

Cheers,

Josh

On Sat, Jul 28, 2012 at 10:49 AM, Erin Hodgess <erinm.hodgess at
gmail.com> wrote:
> Dear R People:
>
> I am using a Linux system in which I have about 3000 files.
>
> I would like to randomly select about 45 of those files to be processed in
R.
>
> Could I make the selection in R or should I do it in Linux, please?
>
> This is with R-2.15.1.
>
> Thanks,
> erin
>
>
> --
> Erin Hodgess
> Associate Professor
> Department of Computer and Mathematical Sciences
> University of Houston - Downtown
> mailto: erinm.hodgess at gmail.com
>
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.


-- 
Joshua Wiley
Ph.D. Student, Health Psychology
Programmer Analyst II, Statistical Consulting Group
University of California, Los Angeles
https://joshuawiley.com/

Hello,

If the files are to be processed in R select a random sample in R.
Using list.files() you can assign a character vector with the filenames 
of interest and then sample from that vector.

?list.files
filenames <- list.files(path, pattern)

rand.sampl <- sample(filenames, 45)

Hope this helps,

Rui Barradas

Em 28-07-2012 18:49, Erin Hodgess escreveu:
> Dear R People:
>
> I am using a Linux system in which I have about 3000 files.
>
> I would like to randomly select about 45 of those files to be processed in
R.
>
> Could I make the selection in R or should I do it in Linux, please?
>
> This is with R-2.15.1.
>
> Thanks,
> erin
>
>