title: Creating a flag swimlane chart in D3.js
body: <p><img src="https://i.stack.imgur.com/jTrBH.png" alt="flag activity chart"></p>
  
  <p>Is there a way in D3.js to create the shown chart to represent activity (on/off) of a set of flags?  The data feeding it would look something like:</p>
  
  <pre><code>datetime,flag1,flag2,flag3,flag4,none
  6/29/2015 06:45:36,1,0,0,1,0
  6/29/2015 06:47:05,1,1,0,1,0
  6/29/2015 07:20:22,1,1,0,0,0
  6/29/2015 07:20:46,0,1,1,0,0
  6/29/2015 07:20:59,0,0,0,0,1
  </code></pre>
  
  <p>I am hoping to have something where the x-axis scales time appropriately (which my representation does not do).  It is assumed that the flag stays in the same state between successive records.  Thanks!</p>