title: octave/matlab read text file line by line and save only numbers into matrix
body: <p>I have a question regarding octave or matlab data post processing.
  I have files exported from fluent like below:</p>
  
  <pre><code>                     "Surface Integral Report"
  
         Mass-Weighted Average
            Static Temperature                  (k)
  </code></pre>
  
  <hr>
  
  <pre><code>          crossplane-x-0.001            1242.9402
            crossplane-x-0.025            1243.0017
            crossplane-x-0.050            1243.2036
            crossplane-x-0.075            1243.5321
            crossplane-x-0.100            1243.9176
  </code></pre>
  
  <p>And I want to use octave/matlab for post processing. 
  If I read first line by line, and save only the lines with "crossplane-x-" into a new file, or directly save the data in those lines into a matrix. Since I have many similar files, I can make plots by just calling their titles.
  But I go trouble on identify lines which contain the char "crossplane-x-". I am trying to do things like this:</p>
  
  <pre><code>clear, clean, clc;
  % open a file and read line by line
  fid = fopen ("h20H22_alongHGpath_temp.dat");
  % save full lines into a new file if only chars inside
  txtread = fgetl (fid)
  num_of_lines = fskipl(fid, Inf);
  char = 'crossplane-x-'
  for i=1:num_of_lines,
    if char in fgetl(fid)
      [x, nx] = fscanf(fid);
      print x
    endif
  endfor
  fclose (fid);
  </code></pre>
  
  <p>Would anybody shed some light on this issue ? Am I using the right function ? Thank you.</p>