title: Combining numpy multi-dimensional arrays
body: <p>I.m facing a little issue to combine arrays in a certain manner.
  Let's say we have</p>
  
  <pre><code>a=array([[1,1,1],[2,2,2],[3,3,3]])
  
  b=array([[10,10,10],[20,20,20],[30,30,30]])
  </code></pre>
  
  <p>I wish to get</p>
  
  <pre><code>c=array([[[1,1,1],[10,10,10]],[[2,2,2],[20,20,20]],[[3,3,3],[30,30,30]]])
  </code></pre>
  
  <p>The real issue is that my arrays a and b are much longer than 3 coordinates!</p>
  
  <p>The best I achieved using concatenate is:</p>
  
  <p><code>concatenate((a,b),axis=2)</code></p>
  
  <p>which results in</p>
  
  <p><code>array([[ 1,  1,  1, 10, 10, 10],
         [ 2,  2,  2, 20, 20, 20],
         [ 3,  3,  3, 30, 30, 30]])</code></p>
  
  <p>it is pretty good but not have enough depth.</p>
  
  <p>Also, I've tried something from another question to get the desired depth:</p>
  
  <p><code>d=concatenate((a[...,None],b[...,None]),axis=2)</code></p>
  
  <p>but results in:</p>
  
  <pre><code> array([[[ 1, 10],
      [ 1, 10],
      [ 1, 10]],
  
     [[ 2, 20],
      [ 2, 20],
      [ 2, 20]],
  
     [[ 3, 30],
      [ 3, 30],
      [ 3, 30]]])
  </code></pre>
  
  <p>Which still does not works...</p>