title: numpy: extending arrays along a new axis?
body: <p>Surely there must be a way to do this... I can't work it out.</p>
  
  <p>I have a (9,4) array, and I want to repeat it along a 3rd axis 4096 times... So it becomes simply (9,4,4096), with each value from the 9,4 array simply repeated 4096 times down the new axis.</p>
  
  <p>If my dubious 3D diagram makes sense (the diagonal is a z-axis)</p>
  
  <pre><code>4|   /off to 4096
  3|  /
  2| /
  1|/_ _ _ _ _ _ _ _ _ 
     1 2 3 4 5 6 7 8 9
  </code></pre>
  
  <p>Cheers</p>
  
  <p>EDIT: Just to clarify, the emphasis here is on the (9,4) array being REPEATED for each of the 4096 'rows' of the new axis. Imagine a cross-section - each original (9,4) array is one of those down the 4096 long cuboid.</p>