A simple Canvas markers.js scaled-point generator

<!DOCTYPE html>
<html>
  <head>
    <title>crime clusters</title>
    <script type='text/javascript'
        src='https://mapbox.com/markers.js/dist/markers.0.5.3.min.js'></script>
    <script type='text/javascript'
        src='https://mapbox.com/markers.js/dist/markers.0.5.3.externals.js'></script>
    <script type='text/javascript'
        src='scale_factory.js'></script>
    <link href='https://mapbox.com/markers.js/dist/markers.0.5.3.css'
    rel='stylesheet' type='text/css' />
    <style>
        body { font: 14px/20px 'Helvetica', 'Helvetica Neue'; background:#eee; }
        #map {
            position:absolute;
            top:0;
            left:0;
            width:640px;
            height:400px;
        }
    </style>
  </head>
  <body>
    <div class='map' id='map'>
    </div>
    <script type='text/javascript'>
      wax.tilejson('https://a.tiles.mapbox.com/v3/tmcw.map-bzuvyug3.jsonp',
        function(tj) {
          var m = new MM.Map('map', new wax.mm.connector(tj));
            mapbox.csv_url_to_geojson('texas_crime.csv', function(crimes) {
                var ml = mapbox.markers()
                    .factory(scale_factory)
                    .features(crimes);
                m.addLayer(ml);
                m.extent(ml.extent());
                mmg_interaction(ml);
            });
        });
    </script>
  </body>
</html>