Combining multiple csv files in to one

Hello ,

I have files titled in a particular order File1.csv , File2.csv .... and so on. The files contain two colums of data. I would like to combine the second column of each of the csv files into one excel file. I tried the following code snippet but resulted in output variables like filenames being blank

fileDir = 'D:\excel_folder';

outfile = 'D:\MASTER.xls';

addpath(fileDir);

fileNames = dir(fileDir);

fileNames = {fileNames.name};

fileNames = fileNames(cellfun(...

@(f)~isempty(strfind(f,'.csv')),fileNames));

for f = 1:numel(fileNames),

[~, ~, raw] = xlsread( fullfile(fileDir, fileNames{f}));

xlswrite(outfile, raw, fileNames{f});

end

Any help is appreciated

Answer 1

[Mathieu NOE]

hello

this is an alternative that worked on my pc. There may be better coding options, I admit I had a bit of a hard time figuring out why writecell did not give the expected result with an array of cells of different size. Maybe someone else will bring this later on

but so dar so good :

and also I add natsortfiles to make sure the input files are sorted according to the natural order (from the numerical values in the filename)

fileDir = cd;

outfile = 'MASTER.xlsx';

fileNames = dir(fullfile(cd,'*.csv')); % get list of files in directory
fileNames_sorted = natsortfiles({fileNames.name}); % sort file names into order
M= length (fileNames_sorted);

for f = 1:M 
    raw = csvread( fullfile(fileDir, fileNames_sorted{f}));
    out{f} = raw(:,2);
end

% padd NaNs for shorter arrays - do we have another solution ? 
    maxSize = max(cellfun(@numel,out));    %# Get the maximum vector size
    fcn = @(x) [x ; nan(maxSize-numel(x),1)];  %# semicolon here                
    rmat = cellfun(fcn,out,'UniformOutput',false);  %# Pad each cell with NaNs
    
% writecell(rmat,fullfile(cd,outfile)); % why this does not work ??
writematrix(cell2mat(rmat),fullfile(cd,outfile)); % work around