title: Problems encountered with the Q-Vector Example of MetPy
body: <p>I'm trying to reproduce the <a href="https://unidata.github.io/python-gallery/examples/850hPa_QVectors.html" rel="nofollow noreferrer">Q-Vector example in MetPy</a>, and am getting an error when applying the command: </p>
  
  <pre><code>q_div = -2*mpcalc.divergence(uqvect, vqvect, dx, dy, dim_order='yx')
  </code></pre>
  
  <blockquote>
    <p>Error: 
    ValueError: <code>divergence</code> given arguments with incorrect units: <code>u</code> requires "[speed]" but given "meter ** 2 / kilogram / second", <code>v</code> requires "[speed]" but given "meter ** 2 / kilogram / second".</p>
  </blockquote>
  
  <p>I don't know how to circumvent this problem, because <code>uqvect</code> and <code>vqvect</code> must have the units <code>meter**2/kilogram/second</code>. Any ideas? Or is there a general problem with the MetPy Code, because I just took the code from the MetPy Homepage.</p>