title: Matlab - save(int2str(i), x) doesn't work - Argument must contain a string
body: <p>I have a loop which is generating some data and in certain cases I want to save the data. Therefore I have:</p>
  
  <pre><code>save(int2str(i), x);
  </code></pre>
  
  <p>This doesn't work and comes out with the message:</p>
  
  <pre><code>??? Error using ==&gt; save
  Argument must contain a string.
  </code></pre>
  
  <p>What am I doing wrong?</p>