======= Mathematica Batch Jobs =======


=== SLURM ===

In order to be able to use Mathematica, you need to load the program with the ''module load'' command
<code>
[username@l32]$ module load Mathematica    # load the default Mathematica module
[username@l32]$ module list                # check loaded modules
Currently Loaded Modulefiles:
  [...] 
      18) Mathematica/12.3.1 
</code>

(See also the introduction to the [[https://wiki.vsc.ac.at/doku.php?id=doku:slurm|module command.]])
Now, Mathematica can be called by
<code>
[username@l32]$ math 
</code>

==== Example: Parallel Mathematica Task ====

Mathematica script example ''math-vsc3.m'':
<code>

GetEnvironment["MATH_BIN"]
math = Environment["MATH_BIN"]
kernelsperhost = 16
hosts=Import["nodelist","List"];



Needs["SubKernels`RemoteKernels`"]
$RemoteCommand = "ssh -x -f -l `3` `1` " <> math <> " -mathlink -linkmode Connect `4` -linkname '`2`' -subkernel -noinit" 


(* first host with one kernel less *)
LaunchKernels[RemoteMachine[hosts[[1]], kernelsperhost-1]];

imin=2;
imax=Length[hosts];
idelta=1;

Do[ 
        LaunchKernels[RemoteMachine[hosts[[i]], kernelsperhost]];
        , {i, imin, imax, idelta}] 

primelist = ParallelTable[Prime[k], {k, 1, 20000000}];
Print[primelist]
</code>

sbatch job script 
''jobPar.sh'':
<code>
#!/bin/bash
#
#SBATCH -J par
#SBATCH -N 2
#SBATCH -L mathematica@vsc


module purge
module load Mathematica/10.0.2 # load desired version


export MATH_BIN=`which math`
#export MATH_PROC=16
scontrol show hostnames $SLURM_NODELIST > nodelist
#execute prolog for getting access to license everywhere
srun hostname


math -run < math-vsc3.m
</code>

<code>
[username@l32]$ sbatch jobPar.sh      # submit your job
[username@l32]$ squeue -u username    # check state of your job
</code>

==== remote kernel connection ====

The setup follows
[[https://cc-mathematik.univie.ac.at/services/vsc3-cluster/remote-mathematica-kernel/|Local mathematica with remote kernel]]
with the

**Shell command to launch kernel:**

for VSC3+
<code>
/Users/<LOCAL-USERNAME>/Library/tunnel.sh <VSC-USERNAME>@localhost:9998 /opt/sw/x86_64/generic/Mathematica/11.3/bin/math `linkname`
</code>

for VSC4
<code>
/Users/<LOCAL-USERNAME>/Library/tunnel.sh <VSC-USERNAME>@localhost:9998 /opt/sw/vsc4/VSC/x86_64/generic/Mathematica/12.3.1/bin/math `linkname`
</code>

Note that on VSC4, the salloc command [as described on the
cc-mathematik.univie.ac.at web link] does not need the Mathematica
license. Just leave the -L parameter away.