Loading an R Module
-------------------

To use R on the ARC systems you simply need to load the latest R environment module,  
in this example version 4.4.0 - it can be loaded using the following command::
 
  module load R/4.4.0-gfbf-2023a
To see all versions of R we have available, use the command ::
 
  module spider R 

The base install has many popular R packages installed. Additionally there are older modules available with the ``-ARC`` suffix
e.g. ``R/4.2.2-foss-2022a-ARC`` these modules load many more R libraries than the base R installation and contains those libraries
most requested by ARC users. It is possible that you will need access to libraries which are not installed in the base or ARC R modules.
You can install R libraries in an R library repository within your storage area (e.g. $HOME or $DATA) please see below.
 
Please note: Some R libraries depend on the existence of non-R applications or other shared binaries. Attempting to install an R library
with binary dependencies may fail. In this case please contact the ARC team and we will install the dependencies for you centrally. 

Typical R submission script
===========================

The following is an example of a typical R submission script for ARC::

  #!/bin/bash
  #SBATCH --nodes=1
  #SBATCH --ntasks-per-node=1
  #SBATCH --cpus-per-task=8
  #SBATCH --partition=short
  #SBATCH --time=12:00:00
  #SBATCH --job-name=Rtest
  
  module purge
  module load R/4.4.0-gfbf-2023a 
  
  Rscript --no-restore --no-save r_script.R
  
The script above requests a single node and 8 cores. You will need to ensure your R script is written using R parallel libraries in order to make use of these CPU 
resources.