Matlab on AWS doesn't seem to recognize (@)Class-folders

Hi,

I recently started working with the Parallel Computing Toolbox and now I want to extend the performance by using the AmazonWebServices. For simple scripts this works fine already.

Now I want to segment some neuroimaging data using the SPM12-toolbox. Parallel-Computing on my local computer doesn't cause any problems, but when use AWS, I get the following Error:

"An UndefinedFunction error was thrown on the workers for 'list'. This might be because the file containing 'list' is not accessible on the workers. Use addAttachedFiles(pool, files) to specify the required files to be attached. For more information see the documentation for 'parallel.Pool/addAttachedFiles'.

... Caused by: Undefined function 'list' for input arguments of type 'cell'."

The function "list" is located in a class folder "@foldername". When I copy "list" into a path folder, "list" is recognized and I get an error for the function "match", which is located in another class folder. However, when I put every function into a single path folder SPM12 crashes (they must have had a reason to do this). So that doesn't seem to be a solution.

addAttachedFiles(gcp,{'C:\...\@foldername\list.m'}) doesn't add "list" to AWS either.

Does anybody know a workaround for this problem?

Best regards, Sander

Answer 1

[Philip Borghesani]

You must add the complete @foldername folder. The clue here is Caused by: Undefined function 'list' for input arguments of type 'cell'." Your class was not correctly copied to the worker machines (most likely because the constructor was not found) and was converted to a structure.

[Sander Groeneweg]

Unfortunately I still get the same error message:

"Error using cfg_repeat/list (line 112) An UndefinedFunction error was thrown on the workers for 'list'. This might be because the file containing 'list' is not accessible on the workers. Use addAttachedFiles(pool, files) to specify the required files to be attached. For more information see the documentation for 'parallel.Pool/addAttachedFiles'.

Caused by: Undefined function 'list' for input arguments of type 'cell'."

As you recommended I added the @foldernames via

addAttachedFiles(gcp,{'C:\...\@foldername'})

resulting in gcp:

Attached files for parallel pool:

C:\Program Files\MATLAB\spm12\spm12\matlabbatch\@cfg_branch
C:\Program Files\MATLAB\spm12\spm12\matlabbatch\@cfg_choice
C:\Program Files\MATLAB\spm12\spm12\matlabbatch\@cfg_const
C:\Program Files\MATLAB\spm12\spm12\matlabbatch\@cfg_dep
C:\Program Files\MATLAB\spm12\spm12\matlabbatch\@cfg_entry
C:\Program Files\MATLAB\spm12\spm12\matlabbatch\@cfg_exbranch
C:\Program Files\MATLAB\spm12\spm12\matlabbatch\@cfg_files
C:\Program Files\MATLAB\spm12\spm12\matlabbatch\@cfg_intree
C:\Program Files\MATLAB\spm12\spm12\matlabbatch\@cfg_inv_out
C:\Program Files\MATLAB\spm12\spm12\matlabbatch\@cfg_item
C:\Program Files\MATLAB\spm12\spm12\matlabbatch\@cfg_leaf
C:\Program Files\MATLAB\spm12\spm12\matlabbatch\@cfg_mchoice
C:\Program Files\MATLAB\spm12\spm12\matlabbatch\@cfg_menu
C:\Program Files\MATLAB\spm12\spm12\matlabbatch\@cfg_repeat

[Oli_ee]

Hi, Philip, have you got any solution for this problem. I got the same error message today, and if you have solved the problem, it will be greatly apprecitated that you may share your solution. Thankyou.

Answer 2

[Oli_ee]

I occurently found that if I shut downd the parralle pool first, and then run the draft, it was ok.