Set display resolution for Matlab with SLURM

Question

I use to run some Matlab simulations on a HPC cluster.

The cluster runs SLURM.

One of the outputs of my Matlab script is a GIF file which shows the time evolution of what I am simulating. Every frame of the GIF file is obtained by means of the command "getframe", which takes a snapshot of the display.

When I run the Matlab script on my computer, the GIF file looks perfect, as the snapshot has the resolution of my computer. When I run the same Matlab script on the HPC cluster, submitting the job through SLURM, the GIF file looks bad, as it features a very low resolution. After all, the HPC cluster has not an actual display, maybe just a virtual display.

So, here is my question: can I change the resolution of the virtual display when I submit the job, so that the snapshots which Matlab takes during the simulation look high-resolution?

Answer 1

Try adding the following before the call to getframe :

h = figure;
h.WindowState = 'maximized';

This will make sure the window is maximised before the snapshot is captured. You then should get a higher resolution image.

If that does not work, another option is to save each image to disk with print , where you can specify the resolution explicitly:

print('-dpng', '-r200', filename)

but then you will have to merge all the files in a movie in a subsequent step.