Saving output files as input file names while running though a for loop

I am attempting to run a filtering function on multiple csv files each names a unique date (e.g., '20220527.csv', '20220528.csv', etc.).

Is there a way I can run the function in the for loop and save the output as a csv file taking the input file name (e.g., 'Filt20220527'.csv) for each of the unique files so I each file is different with it's corresponding input filename? I'd also like to have the 3 variable names per file automatically update for each file as they are all different (e.g., 'x532', 'y532', 'Timestamp' and the next file would be 'x533', 'y533', 'Timestamp')

%%%cd ('....my path....')

filePattern = fullfile('*.csv');
thefiles = dir(filePattern);

filename = thefiles.name;
%%% Start looping over files
for k= 1:numel(thefiles)
    X= readmatrix(thefiles(k).name);

    X_Table = readtable(thefiles(k).name);

    TMSP = X_Table(:,[3]);

    FilteredSignal = filter(Filter_Butter,X);
    T = array2table(FilteredSignal(:,[1:2])); 

    FiltFinal = [TMSP T];                                               % Create final filtered data table with timestamp
    FiltFinal.Properties.VariableNames = ["x532","y532","Timestamp"]
    
%%%
    %% SAVE
    cd ('...\Filtered_Data');    
    output_name = [FiltFinal, num2str(k) '.csv'];   %Saves as FiltFinal1, 2, 3 etc.. but need to save as input name ('Filt20220527.csv' etc...)

    writetable(FiltFinal,output_name);
    
    %%%cd ('....my path.....')

end

[Jan]

I do not understand, if the posted code is working or if it has a problem.

Avoid changing the current folder by cd(), but use absolute path names. You started to do so with fullfile('*.csv'). Just include the path here also and the code gets cleaner and more stable.

[CAN105]

The code is working but I am trying to modify it as I'll be running hundreds of files and rather not have to manually input the variable names each time and change the name of the csv afterwards.

Thanks for the tip!

[chrisw23]

an idea...

for currFile = string(thefiles)

....

output_name = string(FiltFinal) + currFile + ".csv";

Answer 1

[埃博拉酱]

filenames = struct2table(dir('*.csv')).name;
%%% Start looping over files
for k= 1:numel(filenames)
    X= readmatrix(filenames{k});
    X_Table = readtable(filenames{k});
    TMSP = X_Table(:,3);
    FilteredSignal = filter(Filter_Butter,X);
    T = array2table(FilteredSignal(:,1:2)); 
    FiltFinal = [TMSP T];                                               % Create final filtered data table with timestamp
    FiltFinal.Properties.VariableNames = ["x"+k,"y"+k,"Timestamp"]
    
%%%
    %% SAVE
    writetable(FiltFinal,fullfile('...\Filtered_Data',['Filt',filenames{K}]));
    
    %%%cd ('....my path.....')
end

It's just a simple string concatenation. If your MATLAB doesn't support this operation, it's time for you to update your software.