title: Geometric median of multidimensional points
body: <p>I have an array of 3D points:</p>
  
  <pre><code>a = np.array([[2., 3., 8.], [10., 4., 3.], [58., 3., 4.], [34., 2., 43.]])
  </code></pre>
  
  <p>How can I compute the <a href="https://en.wikipedia.org/wiki/Geometric_median" rel="noreferrer">geometric median</a> of those points?</p>