title: Adding to a legend after each iteration
body: <p>I run</p>
  
  <pre><code>loglog(x,y);
  legend('First script');
  </code></pre>
  
  <p>from the first script.
  Then, <code>hold on;</code>.
  I run a similar second script.
  I see two graphs correctly, but only the initial legend.
  I want to increment the legend from different scripts.</p>
  
  <p><strong>How can you add to the legend from a single script?</strong></p>