title: Using LINQ to create an IEnumerable<> of delta values
body: <p>I've got a list of timestamps (in ticks), and from this list I'd like to create another one that represents the delta time between entries.</p>
  
  <p>Let's just say, for example, that my master timetable looks like this:</p>
  
  <ol>
  <li>10</li>
  <li>20</li>
  <li>30</li>
  <li>50</li>
  <li>60</li>
  <li>70</li>
  </ol>
  
  <p>What I want back is this:</p>
  
  <ol>
  <li>10</li>
  <li>10</li>
  <li>20</li>
  <li>10</li>
  <li>10</li>
  </ol>
  
  <p>What I'm trying to accomplish here is detect that #3 in the output table is an outlier by calculating the standard deviation.  I've not taken statistics before, but I think if I look for the prevalent value in the output list and throw out anything outside of 1 sigma that this will work adequately for me.</p>
  
  <p>I'd love to be able to create the output list with a single LINQ query, but I haven't figured it out yet.  Currently I'm just brute forcing it with a loop.</p>