Warning not being suppressed during parfor loop

I'm running a parfor loop. Within the loop, occasionally the following error is thrown:

Warning: File not found or permission denied

I've attempted to disable this warning on each core (I deal with the cause of the error separately) as follows:

spmd
  warning('off', 'MATLAB:DELETE:PermissionDenied');
end
...
parfor
  do stuff
end

But the warning still occurs.

Does anyone have any thoughts on how I'm going wrong?

Cheers

Answer 1

[Nikilesh Chilkuru]

I have tried to reproduce this issue using a known warning:'MATLAB:rmpath:DirNotFound'

Reproduction Code:

parpool(2)  % creating a parallel pool of two workers
spmd
    warning('off','MATLAB:rmpath:DirNotFound')
end

parfor i = 1:2
rmpath('folderthatisnotonpath')
end

Turning off a warning in spmd suppresses the warning in workers successfully. I believe that the warning you are turning off might be incorrect. To see the identifier of the last issued warning

w = warning('query','last')  % put these two lines in the parfor loop after the line that causes this error
w.identifier % this contains the warning identifier

You can see the identifier of the warning from the field 'identifier' of struct'w' returned by above command. This is the warning you should turn off to suppress that warning. To get more information on how to suppress warnings, refer: Suppress Warnings