title: Error when using xlswrite in Octave
body: <p>I am trying to write a cell array to an Excel spreadsheet in Octave using the <code>xlswrite</code> from the <code>io</code> package in Octave (3.8.0, <code>io</code> 2.0.2 loaded, using Windows 7 64 bit).</p>
  
  <p>The cell array looks like this:</p>
  
  <pre><code>&gt;&gt; pump_backlash(1:3,:)
  ans =
  {
    [1,1] = Machine #
    [2,1] = Machine_01
    [3,1] = Machine_02
    [1,2] = Station #
    [2,2] = 1
    [3,2] = 1
    [1,3] = Pump channel #
    [2,3] = 1
    [3,3] = 2
    [1,4] = Backlash
    [2,4] = 
  
      57  65  62
  
    [3,4] =
  
      58  49  50
  
  }
  </code></pre>
  
  <p>Except it's got many more rows. The first row consists of "headings" (strings), and then after that the first column is a string relating to the machine ID, the second and third columns are integers (scalars), and the fourth column of the cell array are 1x3 vectors of integers (although cells in the 4th column are sometimes empty if the test/measurement failed for whatever reason).</p>
  
  <p>I try to write to Excel using the following command:</p>
  
  <pre><code>&gt;&gt; xlswrite('Pump_cal_results.xlsx',pump_backlash)
  </code></pre>
  
  <p>and the error message I get is as follows: </p>
  
  <pre><code>Creating file Pump_cal_results.xlsx
  error: cellfun: all values must be scalars when UniformOutput = true
  error: called from:
  error:   C:\Octave\Octave-3.8.0\share\octave\packages\io-2.0.2\private\spsh_prstype.m at line 62, column 6
  error:   C:\Octave\Octave-3.8.0\share\octave\packages\io-2.0.2\private\__COM_oct2spsh__.m at line 108, column 10
  error:   C:\Octave\Octave-3.8.0\share\octave\packages\io-2.0.2\oct2xls.m at line 189, column 18
  error:   C:\Octave\Octave-3.8.0\share\octave\packages\io-2.0.2\xlswrite.m at line 178, column 20
  </code></pre>
  
  <p>If I follow the error trail and go to line 62 of <code>\private\spsh_prstype.m</code>, I have:</p>
  
  <pre><code>ptr = cellfun ("isnan", obj);                         ## Find NaNs &amp; set to BLANK
  </code></pre>
  
  <p>So it's obviously got something to do with that function call to <code>cellfun</code>, but I am not sure where to go from there. There are quite a few other function calls to <code>cellfun</code> in <code>spsh_prstype.m</code>.</p>
  
  <p>The closest I have found by searching on the internet is <a href="http://octave.1599824.n4.nabble.com/Re-installing-java-and-apache-for-using-spreadsheet-I-O-td4664767i40.html#a4665447" rel="nofollow">this question</a>, but there is no solution offered.</p>
  
  <p>Any help/suggestions welcome.</p>