title: python: numpy function to expand multiple matrices
body: <p>Assuming I have 3 <code>numpy</code> square matrices of various shapes:</p>
  
  <pre><code>AxA
  BxB
  CxC
  </code></pre>
  
  <p>Is there a <code>numpy</code> function which would expand the matrices to the maximum size and put some default values in new cells? Example:</p>
  
  <pre><code>3x3
  5x5
  10x10
  </code></pre>
  
  <p>should result in 3 10x10 arrays.</p>