title: Most meaningful way to compare multiple time series
body: <p>I need to write a program that performs arithmetic (+-*/) on multiples time series of different date range (mostly from 2007-2009) and frequency (weekly, monthly, yearly...).</p>
  
  <p>I came up with:</p>
  
  <ul>
  <li>find the series with the highest freq. then fill in the other series with zeros so they have the same number of elements. then perform the operation.</li>
  </ul>
  
  <p>How can I present the data in the most meaningful way?</p>
  
  <p>Trying to think of all the possibilities</p>