title: Numpy Vector (N,1) dimension -> (N,) dimension conversion
body: <p>I have a question regarding the conversion between (N,) dimension arrays and (N,1) dimension arrays. For example, y is (2,) dimension.</p>
  
  <pre><code>A=np.array([[1,2],[3,4]])
  
  x=np.array([1,2])
  
  y=np.dot(A,x)
  
  y.shape
  Out[6]: (2,)
  </code></pre>
  
  <p>But the following will show y2 to be (2,1) dimension. </p>
  
  <pre><code>x2=x[:,np.newaxis]
  
  y2=np.dot(A,x2)
  
  y2.shape
  Out[14]: (2, 1)
  </code></pre>
  
  <p>What would be the most efficient way of converting y2 back to y without copying?</p>
  
  <p>Thanks,
  Tom</p>