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import over 1000 files

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i want to change many files including files in subfolders.
but if file outnumber 1001, my code stops.
i'd like to import over 1000 files to "files" struct.
  2 Comments
Jeong Dae Kim
Jeong Dae Kim on 31 Jul 2021
i edited my Question. take a look

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Accepted Answer

Paul Kaufmann
Paul Kaufmann on 4 Aug 2021
Don't know what the problem is with exceeding N=1000. Works for me:
path = "data/"
files = [ dir(fullfile(path,'**','*.txt')); dir(fullfile(path,'**','*.txt')) ]; % do it twice, to exceed 1000
N = numel(files)
Gives this result for my datafolder:
ans = 1890
As I assume you want to rename files or something, you can now just iteratively work on them.
However the following will get you into trouble:
>> numel(files.name)
Warning: Number of elements exceeds maximum flint 2^53-1.
The result may be inaccurate.
ans =
Inf

More Answers (2)

Chunru
Chunru on 31 Jul 2021
You may hit the limit os the number of files that can be opened simutaneously. While it possible to increase the maximum number of opened files in OS, you may want to try open file one by one and then close the file once it is not used.

Image Analyst
Image Analyst on 31 Jul 2021
It will work for more than 1000 files, if you have more than that.
% Specify the folder where the files live.
myFolder = 'G:\';
% Check to make sure that folder actually exists. Warn user if it doesn't.
if ~isfolder(myFolder)
errorMessage = sprintf('Error: The following folder does not exist:\n%s\nPlease specify a new folder.', myFolder);
uiwait(warndlg(errorMessage));
myFolder = uigetdir(); % Ask for a new one.
if myFolder == 0
% User clicked Cancel
return;
end
end
% Get a list of all files in the folder with the desired file name pattern.
filePattern = fullfile(myFolder, '*.png'); % Change to whatever pattern you need.
theFiles = dir(filePattern);
numFiles = length(theFiles)
Result = zeros(numFiles, 1);
for k = 1 : numFiles
baseFileName = theFiles(k).name;
fullFileName = fullfile(theFiles(k).folder, baseFileName);
fprintf('Now reading %s, file #%d of %d.\n', fullFileName, k, numFiles);
% Now do whatever you want with this file name,
% such as reading it in as an image array with imread()
imageArray = imread(fullFileName);
imshow(imageArray); % Display image.
drawnow; % Force display to update immediately.
Result(k) = mean(imageArray(:)); % Whatever you want.
end
  14 Comments
Rik
Rik on 2 Aug 2021
Please show all your code, exactly as you try to use it.

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