MATLAB: How to modify data values for multiple text files

looptxt file

I want to modify the values for multiple text files at the same time how do i do that.
pathname = 'C:\Users\Documents\Shank\Onedrive\MATLAB\2017\2017-07'; % in the folder specified.
files = dir(fullfile(pathname, '*.txt' , ' ReadFcn' , @importdata)); % Get full path names for each text file
numFiles = fullfile({files.folder}, {files.name}); % Get a list of all txt files in the current folder, or subfolders of it.
for k=1:31 %there are 31 .txt files inside 2017-07
filename=sprintf('[208] 2017-07-01%d.txt',k);
T{1:1440,2:38}(T{1:1440,2:38}==0) = NaN; %change athh the zeroes and negative values to NaN
T{1:1440,2:38}(T{1:1440,2:38} < 0) = NaN;
end
there are 31 files and in each file the zeroes and negativs numbers should be changed to NaN. I tried for 1 file how do fo this for 31 .txt files and save them .
Ps. there are 31 folders each folder with 31 files .

Best Answer

txtFiles = dir("*.txt") ;
N = length(txtFiles) ;
for i = 1:N
thisFile = txtFile(i).name ;
% do what you want
end