title: Interweaving two numpy arrays
body: <p>Assume the following arrays are given:</p>
  
  <pre><code>a = array([1,3,5])
  b = array([2,4,6])
  </code></pre>
  
  <p>How would one interweave them efficiently so that one gets a third array like this</p>
  
  <pre><code>c = array([1,2,3,4,5,6])
  </code></pre>
  
  <p>It can be assumed that <code>length(a)==length(b)</code>.</p>