title: Flip 3D numpy Array
body: <p>I need to flip 3D Array A shaped [m, n, k], along the Z axis. 
  I need plane 0 (A[0,:,:]) to become k-1, plane 1 become k-2 plane and so on.</p>
  
  <p>I need to do that on many array's, and loops are very slow.</p>
  
  <p>I tried:</p>
  
  <pre><code>C = numpy.rot90(A,2)
  C = flipud(A)
  C = A[::-1]
  </code></pre>
  
  <p>I tried also rol and reshape, not what I needed.</p>
  
  <p>For example:
  A is (3, 2, 2)</p>
  
  <pre><code>    A= np.array([[[ 1.01551435, -0.76494131],
   [ 0.56853752 , 1.94491724]],
  [[-0.97433012 , 2.08134198],
   [-1.34997602 ,-0.33543117]],
  [[ 0.54217072, -1.33470658],
   [-0.50179028, -0.66593918]]])
  </code></pre>
  
  <p>I need to reorder Z axis upside down:</p>
  
  <pre><code>[[ 0.54217072 -1.33470658]
   [-0.50179028 -0.66593918]]
  [[-0.7703279   0.02402204]
   [-0.18006451 -0.37589744]]
  [[ 1.01551435 -0.76494131]
   [ 0.56853752  1.94491724]]
  </code></pre>
  
  <p>Any ideas ?</p>