title: Multiply array of different size
body: <p>Multiply array of different size.</p>
  
  <pre><code>import numpy as np
  
  a = np.array([1,2,3,4,5])
  
  b = np.array([1,2,3])
  
  print a*b
  </code></pre>
  
  <p>Ofcourse error:</p>
  
  <pre><code>ValueError: operands could not be broadcast together with shapes (5,) (3,)
  </code></pre>
  
  <p>Expected result is np.array([1,4,9,0,0])</p>
  
  <p>How to do?</p>