How to use print in a parfor

Whenever I am using print inside a parfor, I get some all black images. How do I fix this?

Here is a snippet of code and I attached the variables figs and output_files (I had to make them way smaller to upload).

Thanks!!

load('variables.mat')

% output resolution and format
outputDPI = '-r900';
outputFmt = '-dpng';

parfor f = 1:numel(figs)
    figure1 = figs{f};
    output_file = output_files{f};
    if ~isempty(figure1)
        opengl software
        set(groot, 'DefaultFigureRenderer', 'painters');
        print(figure1, output_file, outputFmt, outputDPI);
        close(figure1);
    end %if ~isempty(figure1)
end %for f = 1:numel(figs)

[Raymond Norris]

I can't reproduce the issue, but I don't quite follow the statement I get some all black images. Are you saying that some of the images are all black?

I don't think it'll matter, but you mention that you had to make the figs and output files much smaller. Have you tried running the parfor with the files you uploaded and see the issue? I doubt the larger files would be an issue.

Another thought is to remove opengl. Doubt it will cause the issue, but worth pulling things out to troubleshoot.

[meghannmarie]

It actually makes an all black graphic or a graphic with the legend all messed up (see attached graphics). If you try to run the code in a parfor and a for loop and compare outputs, the graphics are different. I had to make the fig cell array smaller because it exceeded the 5mb limit on the size of file upload on this website. Try this code where I just repeated the cell array 20 times and you should see the bad graphics (I also took the open gl out).

load('variables.mat')
% output resolution and format
outputDPI = '-r900';
outputFmt = '-dpng';
figs = repmat(figs,1,20);
output_files = cell(size(figs));
for n = 1:numel(figs)
    output_files{n} = ['Wind_Rose_' num2str(n,'%02.0f')];
end

parfor f = 1:numel(figs)
    figure1 = figs{f};
    output_file = output_files{f};
    if ~isempty(figure1)
%         opengl software
        set(groot, 'DefaultFigureRenderer', 'painters');
        print(figure1, output_file, outputFmt, outputDPI);
        close(figure1);
    end %if ~isempty(figure1)
end %for f = 1:numel(figs)

[Alvaro]

I am getting this error when using parfor

Error using print
Functionality not supported with figures created with the uifigure function.

and this error when using for

Error using checkArgsForHandleToPrint
Handle input argument contains nonhandle values.

Error in checkArgsForHandleToPrint

Error in print>LocalCreatePrintJob (line 101)
handles = checkArgsForHandleToPrint(0, varargin{:});

Error in print (line 38)
[pj, inputargs] = LocalCreatePrintJob(varargin{:});

In any case, would just running this in serial work out? Or are you trying to speed up the rendering?

[Walter Roberson]

WIth your actual data file, please execute

 cellfun(@(C) isprop(C,'isUIFigure'), figs)

and see if some of them show up as 1 . Any entries that show up as 1 correspond to uifigures -- uifigure have that property but traditional figure do not have that property.