title: How to filter numpy array by list of indices?
body: <p>I have a numpy array, <code>filtered__rows</code>, comprised of LAS data <code>[x, y, z, intensity, classification]</code>.  I have created a <code>cKDTree</code> of points and have found nearest neighbors, <code>query_ball_point</code>, which is a list of indices for the point and its neighbors.</p>
  <p>Is there a way to filter <code>filtered__rows</code> to create an array of only points whose index is in the list returned by <code>query_ball_point</code>?</p>