google maps markerclusterer: weighted markers

see:<div id="map"></div>

by ian_smithz

HTML

<script src="https://maps.google.com/maps/api/js?sensor=false"></script>
<script src="https://google-maps-utility-library-v3.googlecode.com/svn/trunk/markerclusterer/src/markerclusterer.js"></script>
<div id="map_canvas"></div>

CSS

html,body,#map_canvas{margin:0;height:100%;}

JavaScript

function initialize() {
        var center = new google.maps.LatLng(2,2);

        var map = new google.maps.Map(document.getElementById('map_canvas'), {
          zoom: 7,
          center: center,
          mapTypeId: google.maps.MapTypeId.ROADMAP
        });

        var markers = [[1,2,5],[2,1,4],[1.3,1.6,7],[2,2,8],[1.1,1.2,1],[3,1,9],[2.2,1.3,3],[.5,.4,2]];
        for (var i = 0; i < markers.length;++i) {
          
          markers[i]=new google.maps.Marker({position:new google.maps.LatLng(markers[i][0],markers[i][1]),weight:markers[i][2],title:'weight:'+markers[i][2]});
        }
        var calc=function(markers, numStyles) {
          var weight=0;
          
          for(var i=0;i<markers.length;++i){
            weight+=markers[i].weight;
          }

          
            return {
            text: weight,
            index: Math.min(String(weight).length, numStyles)
          };
        }
        
        
        var markerCluster = new MarkerClusterer(map); 
            markerCluster.setCalculator(calc);
            markerCluster.addMarkers(markers)
      }
      google.maps.event.addDomListener(window, 'load', initialize);