In config.php:
addPlugin('PiwikAnalytics', array('piwikroot' => 'stats.smithfam.info/', 'piwikId' => '4'));

Then in the source:
<script type="text/javascript" src="//stats.smithfam.info/piwik.js"> </script>
  <script type="text/javascript">/*<![CDATA[*/ try {
var pkBaseURL = (("https:" == document.location.protocol) ? "https://stats.smithfam.info/" : "http://stats.smithfam.info/");
    var piwikTracker = Piwik.getTracker(pkBaseURL + "piwik.php", 4);
    piwikTracker.trackPageView();
    piwikTracker.enableLinkTracking();
} catch( err ) {} /*]]>*/</script>

Obviously "//stats.smithfam.info/piwik.js" is not going to work. What am I doing wrong?