MATLAB figure export is very slow compared to R

Question

I regularly have to export many figures (hundreds) into a single file. Currently I use

  print('-dpsc2', outfile, '-append');

My code uses a single hidden figure that is being re-used for each new figure.

Now, the problem is that I can achieve a maximum export speed of around 8 figures per second. In R, you can easily plot around 200 figures per second. Does anyone have any suggestions how to (substantially) speed up MATLAB's exporting capabilities?

Jan

Answer 1

I feel your pain. This issue is also why the getframe function for generating movies is so inefficient. The only way I know around it is to write a simpler function that calls the low-level hardcopy function. Here's an example of this for image-based graphics along with some caveats. The hardcopy function supports both the 'dpsc2' and 'append' options that print does:

hardcopy(gcf,'outfile.ps','-dpsc2','-append');

Whereas print(gcf,'-dpsc2', 'outfile.ps', '-append'); takes about 0.12 seconds, the above takes only 0.004 seconds on my machine!

If you do help hardcopy you won't get very much information. However, if you need to reverse engineer anything you can read the code for print (edit print) or the various private functions it calls (e.g., edit private/render, edit private/paperfig, edit private/ghostscript).