title: ValueError: zero-dimensional arrays cannot be concatenated
body: <p>I have the following values, each of which is a scalar of type double: <code>a1, a2, a3, a4, a5</code>.</p>
  
  <p>I tried to concatenate them using Numpy, as follows:</p>
  
  <pre><code>f = np.concatenate((a1,a2,a3,a4,a5))
  </code></pre>
  
  <p>I however get the following error:</p>
  
  <pre><code>ValueError: zero-dimensional arrays cannot be concatenated
  </code></pre>
  
  <p>What could I be doing wrong?</p>
  
  <p>Thanks.</p>