MATLAB crashes when saving figures in a loop

I haven't been able to find any other answers that address this specifically. I'm trying to write a script that generates a bunch of figures and saves them as images, and since there's thousands of images to generate, I'm doing it in a loop.

I've created a simplified script that still reproduces the problem I'm having:

for iteration = 1:1000
    % Generate some data
    x = 1:100;
    y1 = randi(100, 1, 100);
    y2 = y1 + 1;

    % Plot the data
    figure
    hold on
    plot(x, y1, '-r');
    plot(x, y2, '-b');

    % Save an image
    filename = ['iteration' num2str(iteration)];
    saveas(1, [filename '.png']);

    % Close the figures
    close all
end

The above code usually crashes with a Segmentation Violation somewhere around iteration 15 or so.

Any idea what would be causing this to crash? Is there a preferable way to do what I'm trying to do here?

[Fangjun Jiang]

no problem for me running up to 100. Did you check whether you have enough disk space?

[Eric Foote]

I just checked that-- I have 80GB free, but it seems like that should be enough since each image is only around 34kB

[KALYAN ACHARJYA]

Its perfectly works in my case. Have you try to save the image as jpg, this not a strong reason, maybe it works. You can try

1. #Clear the workspace
2. #Exit the Matlab and restart again
3. #First Try 100, if it works then only go for 10000

There are only hit and trials options available to you.

Hope it helps

Answer 1

[OCDER]

I'm suspecting an issue with the graphics card. https://www.mathworks.com/matlabcentral/answers/103051-why-do-i-receive-a-segmentation-violation-related-to-opengl-when-i-display-surface-plots-in-matlab-7.

Try updating your graphics card driver.

Also try this for debugging purposes. If an error occurs, do you see "plotted ok" or "saved ok" as the final message?

for iteration = 1:10
    x = 1:100;
    y1 = randi(100, 1, 100);
    y2 = y1 + 1;

      FH = figure('visible', 'off');  %<=visible off. Tracking figure handle as FH.
      hold on
      plot(x, y1, '-r');
      plot(x, y2, '-b');
    disp('plotted ok');  %Debugging, no message = error in plotting
      saveas(FH, sprintf('iteration%d.png', iteration));  %Using sprintf 
    disp('saved ok');    %Debugging, no message = error in saving
      close all
  end

Or try the "painters" renderer when saving. Replace the saveas with print.

print(FH, sprintf('iteration%d.png', iteration), '-dpng', '-r300', '-painters');

[Eric Foote]

It's possible that setting visible to 'off' may have fixed things-- it seems to have kept things from crashing at least in the simple test program I made. I'm going to see if that works with what I was originally trying to do.