title: Initialized empty numpy array is not really empty (contains zeros)
body: <p>In order to store many 3D points coordinates tuples in a <code>numpy.ndarray</code> I initialize an empty numpy array before entering a loop for each of some features.</p>
  <p>To do so, I currently do this before entering the loop:</p>
  <pre><code>import numpy as np
  pointsarrray = np.empty((1,3))
  </code></pre>
  <p>but this results in an array which is all but empty:</p>
  <pre><code>array([[  5.30498948e-315,   0.00000000e+000,   7.81250000e-003]])
  </code></pre>
  <p>When filling <code>pointsarray</code> in my loop after, I do this:</p>
  <pre><code>pointsarray = np.vstack((pointsarray, [np.array(myPoint)]))
  </code></pre>
  <p>(it also works with np.append)</p>
  <p>and I finally need to delete the <strong>first</strong> line of the array after exiting the loop because this first line always contains the values from the initialization step!</p>
  <p>It's not a big deal but I wonder if there is a cleaner way to achieve a <strong>really</strong> empty array, I mean; with nothing inside it (it shows 1 row yet, I can not figure out why) but at the right dimensions?</p>