exportgraphics in MATLAB online only gives empty PNG-file.

Hi everybody,

I really cannot figure out what I am doing wrong here. When I run this code in a .m-file on MATLAB online (R2022a, Update 4), I only get an empty png file (0KB). It used to work well.. Also manually saving the file to the online folder gives a 0KB PNG-file.

Must be something about the gca, I guess.

t= [0 60 163 204  282 361 415 460 560 761];
U = [9.05 8.00 6.44 6.00 5.18 4.41 4.00 3.61 2.98 2.00];
plot(t,U);

%title and stuff
title('Grafic to export');
xlabel('X-factor');
ylabel('I don''t know Y ');

%export
ax = gca;
filename='ExportTest.png';
exportgraphics(ax,filename);

I appreciate your help and thanks a lot.

C.

EDIT: It works when I run exportgraphics on the command line. But why wont it export when it runs in the .m-file?

Answer 1

[Richard Quist]

Your original code looks like it should work - I suggest contacting support for help.

In the meantime, you could try the following 2 potential work arounds

Workaround #1: add a call to drawnow before the call to exportgraphics. If it's a timing issue where the plot wasn't drawn when exportgraphics started to process it then this may help.

% ...
% ^^^ your original code to create the plot ^^^
filename='ExportTest.png';

% NEW: call drawnow to give the plot a chance to render
drawnow;

% your export call
exportgraphics(ax,filename);

Workaround #2: Rather than use gca, try creating the axes separately and then using that axes handle when plotting your data, adding the title, etc, and in the call to exportgraphics.

ax = axes;
t= [0 60 163 204  282 361 415 460 560 761];
U = [9.05 8.00 6.44 6.00 5.18 4.41 4.00 3.61 2.98 2.00];
plot(ax, t,U); % <<= use ax here
%title and stuff
title(ax, 'Grafic to export'); % <<= use ax here
xlabel(ax, 'X-factor'); % <<= use ax here
ylabel(ax, 'I don''t know Y '); % <<= use ax here
%export
%ax = gca; % <<= Don't use gca here
filename='ExportTest.png';
exportgraphics(ax,filename);