How can I write to a txt file dynamically?

I want to save this form to a text file:

 Col1 Col2 Col3 ..... ColN       % Text File Heading
   4    45  345 .....   34
  34    88  455 .....   73

Note: The number of columns "N" is variable.

I need an expression that is a function in "N" inside a loop (1:N)

[nanren888]

Can you ask the question again in different words?

[Ahmed Elkady]

To make it more easier. I need an expression where I specify a value "N" and then it automatically writes Col1 Col2 Col3 up to ColN in the text file as shown earlier.

Answer 1

[venkat vasu]

A = round(rand(6,7)*9);  % Write this to file.
 fid = fopen('Mymatrix.csv','wt');

     c='col';
  for i = 1:size(A,2)
      fprintf(fid,'%s=%d\t',c,i);
  end
  fprintf(fid,'\n');
    for ii = 1:size(A,1)
      fprintf(fid,'%g\t',A(ii,:));
      fprintf(fid,'\n');
  end
  fclose(fid);

this may help you...

[Ahmed Elkady]

Thank you .. very helpful

Answer 2

[Oleg Komarov]

A = [ 4 45 345 34
     34 88 455 73];

% Number of columns

    N = 2;

% Create/open file discarding content

    fid = fopen('test.txt','w');

% Write header

    fmt = sprintf('Col%d\t',1:N);
    fprintf(fid,[fmt(1:end-1) '\r\n']);

% Write data

    fmt = repmat('%.f\t',1,N);
    fprintf(fid, [fmt(1:end-2) '\r\n'],A');

    fclose(fid);

[Ahmed Elkady]

Thank you .. very helpful