title: calculate distance from all points in numpy array to a single point on the basis of index
body: <p>Suppose a 2d array is given as:</p>
  
  <pre><code>arr = array([[1, 1, 1],
               [4, 5, 8],
               [2, 6, 9]])
  </code></pre>
  
  <p>if <code>point=array([1,1])</code> is given then I want to calculate the euclidean distance from all indices of <code>arr</code> to point (1,1). The result should be</p>
  
  <pre><code>array([[1.41  , 1.        , 1.41],
         [1.    , 0.        , 1.  ],
         [1.41  , 1.        , 1.41]])
  </code></pre>
  
  <p>For loop is too slow to do these computations. Is there any faster method to achieve this using numpy or scipy?</p>
  
  <p>Thanks!!!</p>