How can I filter multiple files ?
I have made a filter as following [b,a] = butter(9,.02,'low'); x=textread('noisy.out'); y=filter(b,a,x); save filtered.out y -ASCII I have 1000 files and I would like to filter all my files using the above filter. Is there any way that I can do this efficiently? my files are named like 1.out 2.out , ... 1000.out any suggestion would be appreciated. my *.out files just include one column with numbers this is one example -4.034E+02 -4.007E+02 -3.987E+02 -3.978E+02 All numbers in one column and each file contains 13000 numbers
Kshitij Singh answered .
2025-11-20
% Retrieve all the files in a directory
names = dir('C:\Users\Oleg\Desktop\Nuova cartella');
names = {names(~[names.isdir]).name};
% Select only the files #.out
idx = ~cellfun('isempty',regexp(names,'\d+\.out'));
names = names(idx);
% Filter
[b,a] = butter(9,.02,'low');
for n = names
% Open file for reading
fid = fopen([myDir n{:}],'r');
x = textscan(fid,'%f');
y = filter(b,a,cat(1,x{:}));
% Discard content and write filtered data
fid = fopen([myDir n{:}],'w');
fprintf(fid,'%E\r\n',y);
fid = fclose(fid);
end