title: "isnotnan" functionality in numpy, can this be more pythonic?
body: <p>I need a function that returns non-NaN values from an array. Currently I am doing it this way:</p>
  
  <pre><code>&gt;&gt;&gt; a = np.array([np.nan, 1, 2])
  &gt;&gt;&gt; a
  array([ NaN,   1.,   2.])
  
  &gt;&gt;&gt; np.invert(np.isnan(a))
  array([False,  True,  True], dtype=bool)
  
  &gt;&gt;&gt; a[np.invert(np.isnan(a))]
  array([ 1.,  2.])
  </code></pre>
  
  <p>Python: 2.6.4
  numpy: 1.3.0</p>
  
  <p>Please share if you know a better way,
  Thank you</p>