How to loop through all files present in several subfolders in a main folder?

Hello!!

I have a main folder (with this directory D:\ABIDEdataset\Outputs\dparsf\nofilt_noglobal\rois_aal) and 16 subfolders (Caltech, KKI, Leuven, Stanford,etc..) in it, with each subfolder containing several *mat files within them. I want to create a loop that goes through all the files coming from all the subfolders and use each file for then perform some calculations.

Thanks in advance!

Answer 1

[Walter Roberson]

https://www.mathworks.com/help/matlab/ref/matlab.io.datastore.filedatastore.html

You can use a filedatastore with a reader function that loads the appropriate variables from the .mat files.

Or you can use dir with ** wildcard:

dinfo = dir('D:\ABIDEdataset\Outputs\dparsf\nofilt_noglobal\rois_aal\**\*.mat');
filenames = fullfile({dinfo.folder}, {dinfo.name});
numfiles = length(filenames);
for K = 1 : numfiles
    thisfile = filenames{K};
    do something with thisfile
end

[Iugo]

Thank you @Walter Roberson!!

I have another question if you don't mind... is it possible for that K run through all the files in a particular subfolder and continue increasing its value when passes to the next subfolder (For example, the first subfolder has 23 subjects, K will then reach 23 and when passes to the 2nd subfolder K will be 24, so on and so on)?

Thank you once again!

[Walter Roberson]

It already does that in practice. Not really guaranteed, though. You could guarantee it by sort(filenames) before you loop.

[Iugo]

I think it worked :)

Because the calculations are kinda big I don't know yet but if I have any doubts I'll let you know @Walter Roberson!!

Once again, thank you so much!