Julia

The Julia programming language is a high-level, high-performance dynamic programming language for technical computing, in the same space as e.g. MATLAB, Scientific Python, or R. For more details, see their web page.

Interactive usage

Julia is available in the module system. By default the latest stable release is loaded:

module load julia
julia

Batch usage

Running Julia scripts as batch jobs is also possible. An example batch script is provided below:

#!/bin/bash
#SBATCH --time=00:01:00
#SBATCH --mem=1G

export OMP_NUM_THREADS=${SLURM_CPUS_PER_TASK:-1}
module load julia
srun julia juliascript.jl

Number of threads to use

By default Julia uses up to 16 threads for linear algebra (BLAS) computations. In most cases, this number will be larger than the amount of CPUs reserved for the job. Thus when running Julia jobs it is a good idea to set the number of parallelization threads to be equal to the number of threads reserved for the job with --cpus-per-task. Otherwise, the performance of your program might be poor. This can be done by adding the following line to your slurm-script:

export OMP_NUM_THREADS=${SLURM_CPUS_PER_TASK:-1}

Alternatively, you can use the blas_set_num_threads()-function in Julia.