Read files in a folder with dates on them

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Hi everyone, I have a folder with multiple.mat files that are named : Profile_YYYY_Mon for example Profile_1990_Jan.mat the monts are Jan Feb Mar until Dec .How can i read each file in the correct chronological order and then use it to do something inside a for loop?

Accepted Answer

Stephen23
Stephen23 on 14 Jun 2023
Edited: Stephen23 on 14 Jun 2023
The actual solution is to parse the filenames that you gave. Lets create some fake files with fake data:
X=1;save Profile_1990_Jan.mat X
X=2;save Profile_1990_Feb.mat X
X=3;save Profile_1990_Mar.mat X
X=4;save Profile_1990_Apr.mat X
Now lets read them in chronological order:
P = '.'; % absolute/relative path to folder where files are saved.
S = dir(fullfile(P,'Profile*.mat')); % alphabetical order.
I = regexp({S.name},'\d+_\w+','match','once');
DT = datetime(I,'InputFormat','y_MMM')
DT = 1×4 datetime array
01-Apr-1990 01-Feb-1990 01-Jan-1990 01-Mar-1990
[~,X] = sort(DT);
S = S(X); % sort into chronological order
for k = 1:numel(S)
F = fullfile(P,S(k).name);
D = load(F);
D.X % do whatever you want with the imported data
end
ans = 1
ans = 2
ans = 3
ans = 4
Another approach without REGEXP:
S = dir(fullfile(P,'Profile*.mat')); % alphabetical order
DT = datetime({S.name},"InputFormat","'Profile'_y_MMM'.mat'")
DT = 1×4 datetime array
01-Apr-1990 01-Feb-1990 01-Jan-1990 01-Mar-1990
[~,X] = sort(DT);
S = S(X); % sort into chronological order.
for k = 1:numel(S)
F = fullfile(P,S(k).name);
D = load(F);
D.X % do whatever you want with the imported data
end
ans = 1
ans = 2
ans = 3
ans = 4
  1 Comment
lena kappa
lena kappa on 14 Jun 2023
Thank you so much @Stephen23! Both answers work but is one better that the other?

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More Answers (2)

Image Analyst
Image Analyst on 14 Jun 2023
Edited: Image Analyst on 14 Jun 2023
How about something like this to sort by file time/date stamp:
folder = pwd; % Wherever you want.
filePattern = fullfile(folder, 'Profile*.mat');
fileList = dir(filePattern);
[~, sortOrder] = sort([fileList.datenum], 'ascend');
fileList = fileList(sortOrder)
allFileNames = fullfile(folder, {fileList.name});
for k = 1 : numel(allFileNames)
thisFileName = allFileNames{k};
fprintf('Now processing "%s" with a date of %s.\n', thisFileName, fileList(k).date);
% Now do something with the file.
end

Image Analyst
Image Analyst on 14 Jun 2023
Edited: Image Analyst on 14 Jun 2023
How about something like this to sort by the 3 letter month string:
months = {'Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec'}
folder = pwd; % Wherever you want.
filePattern = fullfile(folder, 'Profile*.mat');
fileList = dir(filePattern);
[~, sortOrder] = sort([fileList.datenum], 'ascend');
fileList = fileList(sortOrder)
allFileNames = fullfile(folder, {fileList.name})
for k = 1 : numel(months)
indexes = find(contains(allFileNames, months(k)));
for m = 1 : numel(indexes)
thisFileName = allFileNames{indexes(m)};
% See if this filename contains the k'th month.
% If it does, process it. If not, skip it.
fprintf('Now processing "%s" with a date of %s.\n', thisFileName, fileList(indexes(m)).date);
end
end

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