How to process multiple txt files in a loop?

I have multiple txt files in a folder, and I wrote a code to process a single file:

 function output = do(input)

   filename = ('c:\.....');
   fileID = fopen(filename);

   .....
   process data
   ..... 

   output single output 

   fclose(fileID);

   end

What is needed so that MATLAB processes all the files in the folder, and output all output into a single column matrix?

Much Thanks!

Answer 1

[George]

Get an array of file names and loop over that array. e.g.,

files = ['file1.txt' 'file2.txt' 'file3.txt'];
for ii = 1:numel(files)
fid = fopen(files(ii))
...
fclose(fid)
end

or you can use datastore() with the location as a wildcard.

[Terek Li]

But I got more than 100 files, not a good idea to list out all the file names.

[George]

You don't have to type them all in. datastore will let you use a wildcard and dir will let you capture file names in a directory.

[Nayani Ilangakoon]

Hi George, I tried to use datastore to get multiple files to process. Although it shows it has got all the files, I do not know how to pull out data from each file into separate tall arrays. Any help is highly appreciated.

[George]

Datastore is probably not the best solution for that situation. It solves the opposite problem of "I don't care how many files my data is in, I want to aggregate it into a variable". Use dir to get the filenames.

Answer 2

[Massimo Zanetti]

With DIR function you have access to all data in a folder. An example is

%provide the path to your folder as argument
MyFolderInfo = dir('C/...');
%the names of the files are: 
%MyfolderInfo(1).name
%MyfolderInfo(2).name
%etc....
%for example you can run your function DO on each of them
for k=1:size(MyFolderInfo,1)
  out{k} = do(MyFolderInfo(k).name);
end