title: How to stack geography graphs on top of each other?
body: <p>I am drawing a geographic bubble graph (via <code>geobubble()</code>) and I want to overlay a geographic line graph (via <code>geoplot()</code>) on top of it.</p>
  
  <p>I have tried <code>hold on</code>, and it throws out the error <code>Error using hold (line 42)
  Using hold with geobubble is not supported.</code></p>
  
  <p>This script generates a geobubble graph.</p>
  
  <pre><code>longt = rand(10, 1);
  lat = rand(10, 1);
  val = 10*rand(10, 1);
  gb = geobubble(longt, lat, val);
  </code></pre>
  
  <p>And I want to overlay a line graph on top of it</p>
  
  <pre><code>A = [0.1, 0.9];
  B = [0.2, 0.8];
  geoplot([A(1) B(1)],[A(2) B(2)],'g-*')
  </code></pre>