//自定義點聚合圖示
    var sts = [{
      url: "https://a.amap.com/jsapi_demos/static/images/blue.png",
      size: new AMap.Size(32, 32),
      offset: new AMap.Pixel(-16, -16)
    }, {
      url: "https://a.amap.com/jsapi_demos/static/images/green.png",
      size: new AMap.Size(32, 32),
      offset: new AMap.Pixel(-16, -16)
    }, {
      url: "https://a.amap.com/jsapi_demos/static/images/orange.png",
      size: new AMap.Size(36, 36),
      offset: new AMap.Pixel(-18, -18)
    }, {
      url: "https://a.amap.com/jsapi_demos/static/images/red.png",
      size: new AMap.Size(48, 48),
      offset: new AMap.Pixel(-24, -24)
    }, {
      url: "https://a.amap.com/jsapi_demos/static/images/darkRed.png",
      size: new AMap.Size(48, 48),
      offset: new AMap.Pixel(-24, -24)
    }];
    //點聚合
    var cluster = [];
        //新增點聚合方法
        cluster = new AMap.MarkerClusterer(gmap, gpsMarks, {
          zoomOnclick:false,
          styles: sts,
          gridSize: 80
        });

        //設定點聚合最小顯示的限制 當地圖上點小於15個時，直接顯示全部標記
        cluster.setMinClusterSize(15)
        gpsMarks.splice(0,gpsMarks.length)