Csvwrite a matrix with header

Hi,

I have a huge matrix (3000x3000) and I can write to a csv file with csvwrite('filename', cMatrix); But I also have a header defined in cellarray of strings as 'cHeader'. How should I save the matrix with header? In addition, I would also like to transpose the cHeader array to be the first column of the matrix. Is that possible?

Thanks,

Jennifer

[jgg]

Is it absolutely necessary that you export directly to a .csv? The issue is that it's actually a lot easier to write data to an .xls file instead when it is mixed. You can then use the .xls file to save it as a .csv instead. ( http://www.mathworks.com/help/matlab/ref/xlswrite.html )

The way to do this for a .csv is cumbersome, because you have to use low level export functions directly. See here: http://www.mathworks.com/help/matlab/import_export/write-to-delimited-data-files.html#br2ypq2-1 for a tutorial.

Note in either case you want to cast your data to a cell, which should not pose a problem (just use mat2cell); it will also let you add your column vector of labels at that point.

Answer 1

[Joseph Cheng]

simple way is to write the header in using fprintf

cHeader = {'ab' 'bcd' 'cdef' 'dav'}; %dummy header
commaHeader = [cHeader;repmat({','},1,numel(cHeader))]; %insert commaas
commaHeader = commaHeader(:)';
textHeader = cell2mat(commaHeader); %cHeader in text with commas

%write header to file
fid = fopen('yourfile.csv','w'); 
fprintf(fid,'%s\n',textHeader)
fclose(fid)

%write data to end of file
dlmwrite('yourfile.csv',yourdata,'-append');

[JFz]

Thank you!

Let me try and will report back.

[Ugur Keskin]

One comment on this solution: the textHeader is also including a comma at the end of the textHeader. This is not desired since the row of a CSV should not end with a comma.

I think the easiest fix is to add the following:

TextHeader = TextHeader(1:end-1);

This will remove the last comma.

[Guillaume]

Or since R2013a, get rid of most of the lines building the header and simply:

textHeader = strjoin(cHeader, ',');

which will not put an extra comma

Answer 2

[Bhavin Gajjar]

% Below code use the same logic described in above solution and it works fine. % This code shows the random data matrix of size 10x10 has appended in MyData.csv file with % heading of feature number and label

d = rand(10)

for i = 1:size(d,2) if i == 1 header1{i} = ['Label' num2str(i-1)] else

header1{i} = ['feature_' num2str(i-1)]; end end

header = strjoin(header1, ',');

fid = fopen('MyData.csv','w'); fprintf(fid,'%s\n',header) fclose(fid)

dlmwrite('MyData.csv',d,'-append');