Submitting an R array job

In this section, you will create a grid, define a job script, and submit an array job based on this.

Creating the grid - `15 minutes`

Open the file 03_create_grid.R in RStudio.
Go through & run the code step-by-step and explain / figure out with your group what each part does by inspecting the resulting objects.
After line 30, answer the following question: what is the purpose of the column row in the condition grid?

Open the file 04_array_job.R in RStudio.
Again, go through the file line-by-line figuring out what each line does, paying extra attention to the following questions. The clustering part you don't need to run (FORK clusters don't work on non-UNIX systems)
- What does the function plog on line 18 do? Try it out with a few different texts.
- What does the code starting on line 50 do?
- In which chunk (job) is the 234287th line of the condition grid?
- What will the output folder look like after all the chunks are done?
Go to the terminal (next to the console window in RStudio) and run the following code:
```
Rscript 04_array_job.R 12
```
Explain what happens.

Open the file 05_array_job.sh. What does this file do? How much time is scheduled for this job?
Give the job a nice name using #SBATCH --job-name="name"
Upload the whole folder to the supercomputer using the skills you acquired this morning.
Move to the just uploaded project folder using cd
Run the first three jobs on the supercomputer using the SLURM array notation:
```
sbatch -a 1-3 05_array_job.sh
```
Now check your queue to see if the code runs! (squeue)
Monitor the progress of the first job using cat logs/output.1.out.
Talk through what is happening with your group.