Write table with several header lines to file

I would like to write a csv-file with the delimiter ";" and several header lines. The csv-file shold look like the following example in the end:

Header line 1 (string 1)

Header line 2 (string 2)

UTC [yyyy-mm-dd HH:MM:SS.fff] ; vx [m/s] ; vy [m/s] ; vz [m/s]

2017-02-11 23:00:00.000 ; -2.3059 ; 0.2341 ; 0.1177

2017-02-11 23:00:00.002 ; -2.5948 ; 0.1642 ; -0.0821

2017-02-11 23:00:00.004 ; -2.5439 ; 0.2497 ; 0.0270

. . .

I use the following code:

header={'Header line 1 (string 1)' 'Header line 2 (string 2)' 'UTC [yyyy-mm-dd HH:MM:SS.fff]' 'vx [m/s]' 'vy [m/s]' 'vz [m/s]'};

v=Data; % N×3 double matrix of measured velocity values

t=UTCtime; % N×1 datetime array

output_file_csv=filepath; % path and file name of output file

fid = fopen(output_file_csv, 'wt');

for l = 1:numel(header)

fprintf(fid, '%s\n', header{l});

end

fclose(fid);

M={t,v};

dlmwrite(output_file_csv, M, '-append', 'delimiter', ';');

This code created the error message

Error using dlmwrite (line 112)

The input cell array cannot be converted to a matrix.

Answer 1

[Guillaume]

headerlines = {'AG A&K, IG KlimAT';
               'HBI, 2017-02-23 03:46:04';
               '+QSLX 100.7';
               'Zeit ; v3Dx_QSLX100_7_ESTO ; v3Dy_QSLX100_7_ESTO ; v3Dz_QSLX100_7_ESTO';
               'UTC [yyyy-mm-dd HH:MM:SS.fff] ; Stroemungsgeschwindigkeit_3Dx [m/s] ; Stroemungsgeschwindigkeit_3Dy [m/s] ; Stroemungsgeschwindigkeit_3Dz [m/s]'};
filepath = 'somefile.txt';

fid = fopen(filepath, 'wt');
for l = 1:numel(headerlines)
   fprintf(fid, '%s\n', headerlines{l});
end
fclose(fid);
dlmwrite(filepath, yourmatrix, '-append', 'delimiter', ';');  %with optional 'newline', if you wish

[Michael]

Thank you for your quick answer. Unfortunately dlmwrite does not work (see edited question above).

[Guillaume]

You probably can do it with xlswrite but at this point, I'd simply do it with low level functions

fid = fopen(filepath, 'wt');
for l = 1:numel(headerlines);
   fprintf(fid, '%s\n', headerlines{l});
end
UTCtime.Format = 'yyyy-MM-dd HH:mm:ss.SSS';  %May not be needed if UTCtime already use the correct format.
out = [num2cell(UTCtime), num2cell(Data)].';  %put it all in a cell array
fprintf(fid, '%s; %f; %f; %f\n', out{:});
fclose(fid);