百度地图之云图（热图）预警
前几天需要在百度地图上做云图（热图）预警，搜索了一下可以用heatmap实现，但是heatmap只提供了针对谷歌地图的实现，尽管是百度搜索、谷歌搜索齐用，但都得不到解决。没办法，只有自己研究谷歌地图代码，自助者天助之，最终解决。
- html文件(bmaps.html)代码
<!DOCTYPE html> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <title></title> <style type="text/css"> html{height:100%} body{height:100%;margin:0px;padding:0px} #container{width:75%;height:650px;border:1px solid gray;float:left;} #right{width:24%;height:650px;float:left;overflow-y:auto;} img.show{width:300px;height:200px;} </style> <script type="text/javascript" src="http://api.map.baidu.com/api?v=1.4"></script> <script type="text/javascript" src="GeoUtils.js"></script> <script type="text/javascript" src="heatmap.js"></script> <script type="text/javascript" src="heatmap-bmaps.js"></script> </head> <body> <div id="container"></div> <div id="right"> </div> <br /> <script type="text/javascript"> var map = new BMap.Map("container"); map.centerAndZoom(new BMap.Point(104.072284,30.663333), 12); map.addControl(new BMap.NavigationControl({type: BMAP_NAVIGATION_CONTROL_SMALL})); map.enableScrollWheelZoom(); map.disableDoubleClickZoom(); var heatmap = new HeatmapOverlay(map, {"radius":25, "visible":true, "opacity":60}); var testData={ max: 100, data: [{lat: 104.053909, lng:30.661492, count: 20}, {lat: 104.064258, lng:30.671432, count: 10}, {lat: 104.082943, lng:30.678887, count: 30}, {lat: 104.047873, lng:30.679632, count: 40}, {lat: 104.157035, lng:30.818736, count: 50}, {lat: 104.082943, lng:30.678887, count: 60}, {lat: 104.007557, lng:30.736825, count: 70}, {lat: 104.082943, lng:30.606616, count: 80}, {lat: 103.991459, lng:30.678887, count: 100}, {lat: 104.147261, lng:30.639931, count: 5}, {lat: 104.100693, lng:30.706028, count: 6}, {lat: 104.153585, lng:30.589706, count: 7}, {lat: 103.912121, lng:30.595177, count: 8}, {lat: 103.924769, lng:30.602638, count: 10}, {lat: 103.901198, lng:30.603135, count: 56}, {lat: 104.230624, lng:30.56135, count: 78}, {lat: 104.221425, lng:30.551896, count: 10}, {lat: 104.231199, lng:30.598162, count: 20}, {lat: 103.954665, lng:30.772577, count: 11}, {lat: 104.083446, lng:30.720931, count: 5}, {lat: 103.986285, lng:30.717454, count: 8}, {lat: 103.999508, lng:30.624518, count: 30}, {lat: 104.109317, lng:30.642417, count: 40}, {lat: 104.01963, lng:30.698079, count: 3}, {lat: 104.181756, lng:30.641422, count: 5}, {lat: 104.163934, lng:30.592691, count: 7}, {lat: 104.024804, lng:30.745268, count: 8}, {lat: 103.98571, lng:30.718944, count: 14}, {lat: 104.046651, lng:30.739805, count: 17}, {lat: 103.854054, lng:30.664288, count: 18}, {lat: 103.993184, lng:30.630485, count: 30}, {lat: 104.245572, lng:30.723415, count: 40}, {lat: 103.896598, lng:30.735335, count: 10}, {lat: 104.302489, lng:30.634959, count: 50}, {lat: 104.178307, lng:30.537962, count: 7}, {lat: 104.178307, lng:30.537962, count: 44}, {lat: 104.013881, lng:30.755199, count: 32}, {lat: 104.249021, lng:30.638937, count: 10}, {lat: 104.039177, lng:30.682676, count: 15}, {lat: 104.093219, lng:30.679694, count: 18}, {lat: 104.035153, lng:30.6623, count: 80}, {lat: 104.08632, lng:30.689633, count: 100}, {lat: 104.0524, lng:30.647388, count: 30}, {lat: 104.084596, lng:30.654844, count: 50}, {lat: 104.035153, lng:30.632971, count: 10}, {lat: 104.129439, lng:30.648382, count: 60}, {lat: 104.057, lng:30.726892, count: 80}, {lat: 104.163934, lng:30.632971, count: 40}, {lat: 104.028254, lng:30.758675, count: 10}, {lat: 104.151286, lng:30.609103, count: 60}, {lat: 103.963863, lng:30.668761, count: 80}, {lat: 104.072522, lng:30.658821, count: 90}, {lat: 104.004682, lng:30.75371, count: 50}, {lat: 103.970187, lng:30.718944, count: 40}, {lat: 103.975937, lng:30.67224, count: 30}, {lat: 103.966163, lng:30.661803, count: 20}, {lat: 103.965013, lng:30.728382, count: 70}, {lat: 103.970762, lng:30.750234, count: 40}, {lat: 103.969612, lng:30.694601, count: 80}, {lat: 103.990884, lng:30.618551, count: 40}, {lat: 103.969612, lng:30.662797, count: 30}, {lat: 104.069073, lng:30.747751, count: 90}, {lat: 104.119665, lng:30.697086, count: 50}, {lat: 104.135763, lng:30.664288, count: 40}, {lat: 104.066198, lng:30.751227, count: 30}, {lat:104.057575, lng:30.711493, count: 20}, {lat: 104.10874, lng:230.709009, count: 70}, {lat: 104.034003, lng:30.707022, count: 40}, {lat: 104.067923, lng:30.718448, count: 80}, {lat: 104.135188, lng:30.651862, count: 40}, {lat: 104.132888, lng:30.69013, count: 30}, {lat: 104.067923, lng:30.636451, count: 10}] }; map.addOverlay(heatmap); heatmap.setDataSet(testData); </script> </body> </html>
- js文件(heatmap-bmaps.js)代码
function HeatmapOverlay(map,cfg){ this._map=map; this.conf = cfg; this.heatmap=null; this.latlngs=[]; this.bounds=null; } HeatmapOverlay.prototype = new BMap.Overlay(); HeatmapOverlay.prototype.initialize = function(){ var map=this._map; var el = document.createElement("div"); el.style.position = "absolute"; el.style.top = 0; el.style.left = 0; el.style.border = 0; el.style.width = this._map.getSize().width+"px"; el.style.height = this._map.getSize().height+"px"; this.conf.element = el; map.getPanes().markerPane.appendChild(el); this.heatmap=h337.create(this.conf); this._div = el; return el; } HeatmapOverlay.prototype.draw = function(){ var currentBounds = this._map.getBounds(); if (currentBounds.equals(this.bounds)) { return; } this.bounds = currentBounds; var ne = this._map.pointToOverlayPixel(currentBounds.getNorthEast()), sw = this._map.pointToOverlayPixel(currentBounds.getSouthWest()), topY = ne.y, leftX = sw.x, h = sw.y - ne.y, w = ne.x - sw.x; this.conf.element.style.left = leftX + 'px'; this.conf.element.style.top = topY + 'px'; this.conf.element.style.width = w + 'px'; this.conf.element.style.height = h + 'px'; this.heatmap.store.get("heatmap").resize(); if(this.latlngs.length > 0){ this.heatmap.clear(); var len = this.latlngs.length; d = { max: this.heatmap.store.max, data: [] }; while(len--){ var latlng = this.latlngs[len].latlng; if(!BMapLib.GeoUtils.isPointInRect(latlng, currentBounds)){continue;} var divPixel = this._map.pointToOverlayPixel(latlng), screenPixel = new BMap.Pixel(divPixel.x - leftX, divPixel.y - topY); var roundedPoint = this.pixelTransform(screenPixel); d.data.push({ x: roundedPoint.x, y: roundedPoint.y, count: this.latlngs[len].c }); } this.heatmap.store.setDataSet(d); } } HeatmapOverlay.prototype.pixelTransform = function(p){ var w = this.heatmap.get("width"), h = this.heatmap.get("height"); while(p.x < 0){ p.x+=w; } while(p.x > w){ p.x-=w; } while(p.y < 0){ p.y+=h; } while(p.y > h){ p.y-=h; } p.x = (p.x >> 0); p.y = (p.y >> 0); return p; } HeatmapOverlay.prototype.setDataSet = function(data){ var mapdata = { max: data.max, data: [] }; var d = data.data, dlen = d.length; this.latlngs = []; while(dlen--){ var latlng = new BMap.Point(d[dlen].lat, d[dlen].lng); this.latlngs.push({latlng: latlng, c: d[dlen].count}); var point = this.pixelTransform(this._map.pointToOverlayPixel(latlng)); mapdata.data.push({x: point.x, y: point.y, count: d[dlen].count}); } this.heatmap.clear(); this.heatmap.store.setDataSet(mapdata); } HeatmapOverlay.prototype.addDataPoint = function(lat, lng, count){ var latlng = new BMap.Point(lat, lng), point = this.pixelTransform(this._map.pointToOverlayPixel(latlng)); this.heatmap.store.addDataPoint(point.x, point.y, count); this.latlngs.push({ latlng: latlng, c: count }); } HeatmapOverlay.prototype.toggle = function(){ this.heatmap.toggleDisplay(); }
效果图如下：
