Error when plotting in parfor loop

I'd like to plot inside a parfor loop, but am getting an error I don't understand.
parfor i=1:10
figure;
end
Cannot set WindowStyle to 'docked' when MATLAB is
started with no display or when the -noFigureWindows
option is specified.
I have changed my default window style but got the same error
set(0,'defaultfigurewindowstyle','normal')
set(0,'defaultfigurewindowstyle','docked')

1 个评论

Are you running any other code before the loop? What version of MATLAB and parrallel toolbox are your using?

请先登录,再进行评论。

 采纳的回答

I get the following
parfor i=1:5
figure(i)
plot(rand(i*10,1));
saveas(gcf,['temp' num2str(i) '.jpg']);
end
Cannot set WindowStyle to 'docked' when MATLAB is started with no display or
when the -noFigureWindows option is specified.
Maybe I have some default settings that are preventing graphics objects from opening in my parallel workers?

1 个评论

It does sound like you have set(0,'defaultfigurewindowstyle','docked') in effect. Check for a startup.m that might be setting it.

请先登录,再进行评论。

更多回答(5 个)

It is never possible to plot to the display inside any parallel construct. The workers are in separate processes that do not have access to the graphics subsystem.
You would need to either:
  1. Calculate all of the data in the parfor and then do the plotting after the parfor; or
  2. Use parallel.pool.DataQueue or parallel.pool.PollableDataQueue and send() data back to the client to do the plotting such as by using foreach
No other code. The error occurs just after opening a new matlab instance.
I'm using Parallel Computing Toolbox Version 6.11 (R2017b)
To save a figure in a parfor loop you must do the following as found here. Otherwise save the data and plot after as mentioned by Walter.
parfor i=1:5
figure(i)
plot(rand(i*10,1));
saveas(gcf,['temp' num2str(i) '.jpg']);
end
Try the code above and let us know if the error continues.
According to this, it should be possible for parallel workers to plot:
I don't mind my plots being invisible, but I would like to save them to view later.
Note: I get the same error if I use the "plot" command instead of the "figure"command

1 个评论

Note that the plots are not just "invisible": they are in a different process. You would need to save them or else find a way to bring back the figures.

请先登录,再进行评论。

Turns out startup.m was the problem!
I had several default plotting settings, including set(0,'defaultfigurewindowstyle','docked'), in my startup.m
When I comment them all out, I am able to create plots on parallel workers without error.
Thanks Walter and Mark!

2 个评论

Could you clarify this? Are you able to display plots within a forloop? Could you advise what you commented out in order to see these results? Thank you!
You can save plots inside of parfor; you just cannot display them to the user from inside of the parfor.

请先登录,再进行评论。

类别

帮助中心File Exchange 中查找有关 Graphics Performance 的更多信息

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by