matlab matrix to ascii with blank rows

Hello,

I'm trying to export a matrix to ascii file, to then plot it using GNUPLOT. To plot a surface, I would need a matrix with blank rows in it, something like:

A(1) B(1) C(1, 1)
A(1) B(2) C(1, 2)
A(1) B(3) C(1, 3)

A(2) B(1) C(2, 1)
A(2) B(2) C(2, 2)
A(2) B(3) C(2, 3)

but I can't find any documentation about it.

Any idea?

Thanks in advance

[Paulo Silva]

You can't have blank elements in a matrix, use cell instead.

[Matt Tearle]

My question would be: why not just plot in MATLAB?

[maurizio]

Because when I'm going to start writing the PhD thesis, I will include a lot of plots (Letx -> eps) and everytime I used Matlab there was always something I had to fix with CorelDraw. I love Matlab but I've never been 100% satisfied with its plotting capability. Do not get me wrong, it's more than enough to visualize data, but as I sayd I've alaways had to modified the exported eps with another software to reach a publishable quality.

Third, I'm very curious by nature and due to the fact that I will produce a lot of plots in the next months, I think it's a good chance to learn something more about GNUPLOT.

Thanks for your question, bye

Maurizio

Answer 1

[Oleg Komarov]

Look at fprintf

Oleg

Answer 2

[Igor]

better than fprintf :)

dlmwrite

[Oleg Komarov]

You can't use dlmwrite if the OP is actually trying to write A(1,1) and not the element itself ata that position.

And easier to use maybe, don't know about better.

[Walter Roberson]

And you aren't going to get the blank lines in dlmwrite() unless you loop using the row offset and the -append option. fprintf() would be easier.

Answer 3

[maurizio]

Thnks, fprint works perfectly:

A = [1 2 3 4 5;
  5 4 3 2 1;
  1 2 3 4 5];

B = [10 20 30 40 50];

t = [10 20 30];

for l = 1:length(t)
    for m = 1:length(B)
        C(m,1) = t(l);
        C(m,2) = B(m);
        C(m,3)  = A(l,m);
      fid = fopen('PlotVariable.dat', 'a');
      fprintf(fid, '%5.3f %5.3f %5.3f \n', C(m,1:3));
      fclose(fid)
      end
      fid = fopen('VarToPlot.dat', 'a');
      fprintf(fid, '\n');
      fclose(fid)

    end

thanks again

Maurizio