How to alter data (multiply) from all the columns of multiple text files in a folder

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I have multiple text files locate in a folder.The names of the text files varies.How shall call them & multiply all the values inside all the text files with 10^-6 in a loop.
Attached 3 text files for refernces.I've made a small code but its ineffective as file name changes and not a value of numstr.
filenames = 'Path1_Step_0001';
for i = 1:length(filenames)
s{i} = readmatrix (['Path1_Step_' numstr(i).'txt']);

Accepted Answer

Mathieu NOE
Mathieu NOE on 19 Jul 2021
this is my suggestion ... the natural sorting order of the files may not be critical here, but it may be helpful another day , so this is a bonus ... natsortfiles is available from the FEX : Natural-Order Filename Sort - File Exchange - MATLAB Central (
I found to save the data that importdata is a bit faster than readmatrix , I leave it to you to choose the best option;
% reading of data txt files
Folder = cd;
FileList = dir (fullfile(Folder, 'Path1_Step_*.txt'));
FileList_sorted = natsortfiles({}); % sort file names into order
M = numel (FileList_sorted);
for iFile = 1:numel(FileList)
FileName = FileList_sorted{iFile};
FileNamePath = fullfile(Folder, FileName);
% load the data : choose one or the other option
data{iFile} = importdata(FileNamePath); % faster
s{iFile} = readmatrix (FileNamePath); % slower
Sideris Tzid
Sideris Tzid on 18 Nov 2021
Edited: Sideris Tzid on 18 Nov 2021
I'm sorry for my english.
Ummm actually I fixed the "last text" issue.
The problem that remains is that I have a folder which looks like this
each one of the subfolders has its own subfolders and so on.
The script that I'm running at the moment is :
Folder = 'C:\Users\sideris\Desktop\folder example';
FileList = dir (fullfile(Folder, '*.txt'));
FileList_sorted = natsortfiles({}); % sort file names into order
M = numel (FileList_sorted);
for iFile = 1:M
FileName = FileList_sorted{iFile};
FileNamePath = fullfile(Folder,FileName);
s{iFile} = readmatrix (FileNamePath);
data_out = s{iFile}*0.0001;
filename_out = Folder+"\"+[FileName(1:length(FileName)-4) '_out.txt'];
writematrix(data_out, filename_out,"Delimiter","tab");
That script only works if all my text files are in the same folder. Is there any way to make that script read all the txt files from every subfolder?

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