Write a 2D character array to textual file

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Hy everyone,
What would be the best way in terms of computational time to write a 2D character array from Matlab to a textual file?
I've used this:
dlmwrite('file.txt', data, '');
but it is too slow.
I want to write a 2D character array so that each array row is printed on a new line.
Thanks!
  1 Comment
Stephen23
Stephen23 on 6 Sep 2017
Probably the fastest way would be to use fprintf directly. Have you tried that?

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Accepted Answer

Cam Salzberger
Cam Salzberger on 6 Sep 2017
Edited: Cam Salzberger on 6 Sep 2017
Hello Marko,
The most easily read code would probably be to either stick with dlmwrite, or loop through each row and use fprintf on an open file. However, if you want to avoid loops, you could do it like this:
fid = fopen('test.txt','w');
Anew = [A repmat(newline,size(A,1),1)];
fprintf(fid,'%s',Anew.');
fclose(fid);
Appending newlines on the ends of the rows makes it unnecessary to loop row by row. Transposing the array before writing it is necessary because fprintf works in linear indexing order (column-major).
-Cam
  2 Comments
Stephen23
Stephen23 on 6 Sep 2017
Edited: Stephen23 on 6 Sep 2017
A slightly clearer way to add the newline:
Anew = A;
Anew(:,end+1) = newline;
Marko Gulin
Marko Gulin on 6 Sep 2017
Edited: Marko Gulin on 6 Sep 2017
Thank you, all of these answers have helped me :)

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