[R] R or C++ on FreeNX servers

[Gad Abraham]

On Thu, Nov 26, 2009 at 8:00 AM, Murray Jorgensen
<maj at stats.waikato.ac.nz> wrote:
> Hi all,
>
> I have just found out that the machine learning group in our Faculty has a
> lot of spare capacity on their FreeNX servers. I do not know a lot about
> these beasts but I understand that they are a free version of something
> produced by a firm called "NoMachine".

FreeNX is just software for connecting to a desktop remotely, like VNC
(only better). So they probably have some sort of cluster. You don't
need NX unless you want to run an R GUI, which is not a good idea for
long running processes and unreliable network connections. Better to
run it from the terminal (check out GNU screen too).

>
> They are designed for executing parallel algorithms and I thought that they
> might be of use in a project of mine comparing different model-fitting
> algorithms from the point of view of sensitivity to starting values.
>
> Anyway before revealing my near-total ignorance to my computer science
> colleagues I thought I would ask if any of my fellow R users have any
> experience with these things and possibly advice to offer. The CS people
>  are probably using the servers in conjunction with Java or C++ and I could
> possibly use the latter of these. I wondered, though, if R could be used
> directly with such hardware and if so, how the parallelizing would be
> handled.

Assuming it's a Unix/Linux cluster on standard hardware (most likely),
you could just run R as normal (single threaded), or do parallel
processing using packages like Rmpi, snow, multicore, etc.. If you use
MPI, you'll probably need a bit of help setting it up properly.

For starters, see
http://cran.r-project.org/web/views/HighPerformanceComputing.html and
the R-sig-hpc mailing list.


-- 
Gad Abraham
PhD Student, Dept. CSSE and NICTA
The University of Melbourne
Parkville 3010, Victoria, Australia
email: gabraham at csse.unimelb.edu.au
web: http://www.csse.unimelb.edu.au/~gabraham