title: Draw line between two subplots
body: <p>I have two two-by-n arrays, representing 2d-points. These two arrays are plotted in the same figure, but in two different subplots. For every point in one of the arrays, there is a corresponding point i the other array. I want to show this correspondance by drawing a line from one of the subplots to the other subplot. </p>
  
  <p>The solutions i have found are something like:</p>
  
  <pre><code> ah=axes('position',[.2,.2,.6,.6],'visible','off'); % &lt;- select your pos...
   line([.1,.9],[.1,.9],'parent',ah,'linewidth',5);
  </code></pre>
  
  <p>This plots a line in the coordinate system given by the axes call. In order for this to work for me i need a way to change coordinate system between the subplots system and the new system. Anybody know how this can be done?</p>
  
  <p>Maybe there is different way of doing this. If so i would love to know.</p>