For loop to work on files in subfolders, while skipping the first file
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I want todecode my data with tdt on MATLAB. I have a folder, this folder has 70 sub-folders. Each of the 70 sub-folders has four .mat files. I want to work on the 2nd three files while loading the first spm.mat file separately. How do I write a for loop that runs through these files so that after working on the loading the first file, I can work on each of the other 3 files sequentially then move to the next folder. These 3 files start with the letters voi (e g voi 1, voi 2). I used the folowing and got an error message: Dot indexing is not supported for variables of this type.
folders = dir('parent folder path'); % Captures all contents of parent folder
folders = folders([folders(:).isdir]==1); % Filter to just folders
folders = folders(3:end); % Remove unnecessary '.' and '..' directories
for i = 1:length(folders)
path = [folders(i).folder,'\',folders(i).name]; % do work with path variable directing to each child folder.
end
end
2 Comments
Stephen23
on 9 Jul 2022
folders = folders(3:end); % Does NOT remove '.' and '..' directories
https://www.mathworks.com/matlabcentral/answers/1699230-folder-listing-with-dir-on-mac#answer_945260
As Walter Roberson wrote in that last link: "In short: if your code assumes that '.' and '..' are the first two entries in a directory, your code has a bug (even in MS Windows). If your code assumes that directory entries are returned in any sorted order, your code has a bug (in all OS.)"
Monalisa Chikezie
on 11 Jul 2022
Accepted Answer
Image Analyst
on 9 Jul 2022
Here's one way:
topLevelFolder = pwd; % Wherever you want.
filePattern = fullfile(topLevelFolder, '**/*.*');
folders = dir(filePattern); % Captures all contents of parent folder and subfolders
% Filter to just folders
itsAFolder = [folders.isdir]
folders = folders(itsAFolder);
% Get all folder names in a cell array.
folderNames = {folders.folder, folders.name}'
c = contains(folderNames, topLevelFolder)
folderNames = unique(folderNames(c))
% Loop over each folder and subfolder.
for k = 1:length(folderNames)
thisFolder = folderNames{k};
fprintf('Processing folder : "%s".\n', thisFolder)
% do work with path variable directing to each child folder.
end
13 Comments
Image Analyst
on 9 Jul 2022
@Monalisa Chikezie I saw your edit but it doesn't look like you ever tried my solution. Why not? I tried it and it works. Will you try please it?
Monalisa Chikezie
on 11 Jul 2022
Edited: Monalisa Chikezie
on 11 Jul 2022
Monalisa Chikezie
on 13 Jul 2022
Image Analyst
on 13 Jul 2022
@Monalisa Chikezie when I enclose fprintf in tic and toc it shows this:
tic
fprintf('Processing folder : "%s".\n', thisFolder)
toc
Elapsed time is 0.000012 seconds.
but if 12 microseconds is too long for you to wait, then you can certainly comment out that line, though maybe you should cut down on the caffeine. 😄
Monalisa Chikezie
on 13 Jul 2022
Image Analyst
on 14 Jul 2022
What is your top level folder? If it's the root it may take a while to do the dir statement. Step through the code or put in tic and toc to see what's taking up all the time. Attach your actual m-file if you need more help.
Monalisa Chikezie
on 20 Jul 2022
Monalisa Chikezie
on 20 Jul 2022
Image Analyst
on 21 Jul 2022
What is in folderNames? Is it empty?
Monalisa Chikezie
on 21 Jul 2022
Image Analyst
on 22 Jul 2022
Then when you step through it line by line, which line hangs?
Monalisa Chikezie
on 22 Jul 2022
Monalisa Chikezie
on 5 Aug 2022
More Answers (0)
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