title: how to set base index in ublas matrix?
body: <p>I have searched the web but could not find an answer.
  how do I have set base index in the matrix, such that indexes start from values other than zero? for example:</p>
  
  <pre><code>A(-3:1) // Matlab/fortran equivalent
  A.reindex(-3); // boost multi-array equivalent
  </code></pre>
  
  <p>thanks</p>