热力图接口案例

    <!DOCTYPE html>
    <html lang="en">
    <head>
    <!DOCTYPE html>
    <html>
    <head>
        <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
        <meta name="viewport" content="initial-scale=1.0, user-scalable=no" />
        <script type="text/javascript" src="http://api.map.baidu.com/api?v=2.0&ak=vN5VO8968DYOBd28UNSxQSlC4V83Rc5"></script>
        <script type="text/javascript" src="http://api.map.baidu.com/library/Heatmap/2.0/src/Heatmap_min.js"></script>
        <title>热力图功能示例</title>
        <style type="text/css">
            #container{height:207px;179px;}
        </style>
    </head>
    <body>
        <div id="container"></div>
    </body>
    </html>
    <script type="text/javascript">
        var map = new BMap.Map("container");          // 创建地图实例

        var point = new BMap.Point(108.25, 33.05);
        map.centerAndZoom(point, 9);             // 初始化地图，设置中心点坐标和地图级别
        map.enableScrollWheelZoom(); // 允许滚轮缩放
      //石泉老街 108.25281,33.04371
      //燕翔洞 108.160726,32.800537
       //子午银滩 108.07572,33.272254
       //中坝大峡谷 108.138825,32.918189
       //后柳水乡 108.230534,32.937468
       //熨斗古镇 108.169116,32.802236

        var points =[

    {"lng":"108.25281","lat":"33.04371","count":"10123456778"},
    {"lng":"108.160726","lat":"32.800537","count":"23450"},
    {"lng":"108.07572","lat":"33.272254","count":"23450"},
   {"lng":"108.138825","lat":"32.918189","count":"230"},
    {"lng":"108.230534","lat":"32.937468","count":"234560"},
    {"lng":"108.169116","lat":"32.802236","count":"23450"},


    ];


        if(!isSupportCanvas()){
            alert('热力图目前只支持有canvas支持的浏览器,您所使用的浏览器不能使用热力图功能~')
        }
        //详细的参数,可以查看heatmap.js的文档 https://github.com/pa7/heatmap.js/blob/master/README.md
        //参数说明如下:
        /* visible 热力图是否显示,默认为true
         * opacity 热力的透明度,1-100
         * radius 势力图的每个点的半径大小
         * gradient {JSON} 热力图的渐变区间 . gradient如下所示
         * {
                .2:'rgb(0, 255, 255)',
                .5:'rgb(0, 110, 255)',
                .8:'rgb(100, 0, 255)'
            }
            其中 key 表示插值的位置, 0~1.
                value 为颜色值.
         */
        heatmapOverlay = new BMapLib.HeatmapOverlay({"radius":20});
        map.addOverlay(heatmapOverlay);
        heatmapOverlay.setDataSet({data:points,max:100});

        closeHeatmap();

        //判断浏览区是否支持canvas
        function isSupportCanvas(){
            var elem = document.createElement('canvas');
            return !!(elem.getContext && elem.getContext('2d'));
        }

        function setGradient(){
            /*格式如下所示:
            {
                0:'rgb(102, 255, 0)',
                .5:'rgb(255, 170, 0)',
                1:'rgb(255, 0, 0)'
            }*/
            var gradient = {};
            var colors = document.querySelectorAll("input[type='color']");
            colors = [].slice.call(colors,0);
            colors.forEach(function(ele){
                gradient[ele.getAttribute("data-key")] = ele.value;
            });
            heatmapOverlay.setOptions({"gradient":gradient});
        }


            heatmapOverlay.show();

    </script>