就像标题所说我在OpenLayers地图上有一个点矢量,我需要将其变成热图。我已经有了下面的代码(对我来说效果很好)但是我需要添加数千个点(在不同的数据文件中)并且能够使用密度/热图来可视化它。它的当前状态是一个简单的开放街道地图,在世界地图上绘制了一层位置!我会张贴一张图片,但声誉规则......
<!DOCTYPE HTML>
<html>
<head>
<title>AIS Map Template</title>
<script src="http://www.openlayers.org/api/OpenLayers.js"></script>
<script>
function init() {
map = new OpenLayers.Map("mapdiv");
var mapnik = new OpenLayers.Layer.OSM();
map.addLayer(mapnik);
// ADD POINTS TO A LAYER
var pois = new OpenLayers.Layer.Vector("Ships",
{
projection: new OpenLayers.Projection("EPSG:4326"),
strategies: [new OpenLayers.Strategy.Fixed()],
protocol: new OpenLayers.Protocol.HTTP(
{
url: "./AISdecoded.txt",
format: new OpenLayers.Format.Text(
{
extractStyles: true,
extractAttributes: true
})
})
});
// ADD POINTS LAYER TO MAP
map.addLayer(pois);
var layer_switcher= new OpenLayers.Control.LayerSwitcher({});
map.addControl(layer_switcher);
var lonlat = new OpenLayers.LonLat(0,0).transform(
new OpenLayers.Projection("EPSG:4326"), // transform from WGS 1984
new OpenLayers.Projection("EPSG:900913") // to Spherical Mercator
);
var zoom = 1;
map.setCenter(lonlat, zoom);
}
</script>
<style>
#mapdiv { width:900px; height:600px; }
div.olControlAttribution { bottom:3px; }
</style>
</head>
<body onload="init();">
<p>AIS Map Data</p>
<div id="mapdiv"></div>
</body>
</html>
测试数据如下所示:
lat lon title description icon iconSize iconOffset
49.4756 0.13138 227006760 Navigation Status: 0 ship_sea_ocean.png 16,16 -8,-8
51.2377 4.41944 205448890 Navigation Status: 0 ship_sea_ocean.png 16,16 -8,-8
我尝试了各种方法来尝试制作热图,但不幸的是我在Javascript / HTML方面有点缺乏。我在网上看了一些例子,包括OpenLayers提供的earthquake example,但其中99%处理KML文件,因为我需要这个应用程序在本地主机服务器上脱机运行,我不能这样做。 我试图在没有成功的情况下取得成功,其中包括:
var heatmapLayer = new ol.layer.Heatmap({
source: new OpenLayers.Layer.Vector("Ships",
{
projection: new OpenLayers.Projection("EPSG:4326"),
strategies: [new OpenLayers.Strategy.Fixed()],
protocol: new OpenLayers.Protocol.HTTP(
{
url: "./AISdecoded.txt",
format: new OpenLayers.Format.Text(
{
extractStyles: true,
extractAttributes: true
})
})
}),
opacity: 0.9
});
// Create a tile layer from OSM
var osmLayer = new ol.layer.Tile({
source: new ol.source.OSM()
});
// Create the map with the previous layers
var map = new ol.Map({
target: 'map', // The DOM element that will contains the map
renderer: 'canvas', // Force the renderer to be used
layers: [osmLayer, heatmapLayer],
// Create a view centered on the specified location and zoom level
view: new ol.View({
center: ol.proj.transform([2.1833, 41.3833], 'EPSG:4326', 'EPSG:3857'),
zoom: 4
})
});
我觉得这比我想象的要容易得多,但我现在已经尝试这样做了大约一个星期,而我的耐心已接近尾声。如果你知道如何做到这一点特别令人敬畏!但如果你不这样做,你能把我推向正确的方向吗?非常感谢任何帮助,谢谢!
修改
好的,所以我将代码编辑为完全OL3并使用geoJSON方法。它现在看起来像这样:
<!DOCTYPE HTML>
<html>
<head>
<title>AIS Map Template</title>
<script src="http://openlayers.org/en/v3.5.0/build/ol.js" type="text/javascript"></script>
<link rel='stylesheet' href='http://ol3js.org/en/master/css/ol.css'>
<script>
function init() {
var vector = new ol.layer.Heatmap({
source: new ol.source.GeoJSON({
url: './AISdecoded.geojson',
projection: 'EPSG:3857'
}),
opacity: .9
});
var osmLayer = new ol.layer.Tile({
source: new ol.source.OSM()
});
// Create the map with the previous layers
var map = new ol.Map({
target: 'map', // The DOM element that will contain the map
renderer: 'canvas', // Force the renderer to be used
layers: [osmLayer,vector],
// Create a view centered on the specified location and zoom level
view: new ol.View({
center: ol.proj.transform([2.1833, 41.3833], 'EPSG:4326', 'EPSG:3857'),
zoom: 4
})
});
}
</script>
<style>
#map { width:900px; height:600px; }
div.olControlAttribution { bottom:3px; }
</style>
</head>
<body onload="init();">
<p>AIS Map Data</p>
<div id="map"></div>
</body>
</html>
但它仍然无效,只有地图,没有图层。这是我通过this one等示例找到的方法。 Firebug说“TypeError:ol.source.GeoJSON不是构造函数”,但我不知道如何以任何其他方式执行此操作。请停下来,谢谢!
答案 0 :(得分:1)
改变这个:
var vector = new ol.layer.Heatmap({
source: new ol.source.GeoJSON({
url: './AISdecoded.geojson',
projection: 'EPSG:3857'
}),
为:
var vector = new ol.layer.Heatmap({
source: new ol.source.Vector({
url: './AISdecoded.geojson',
projection: 'EPSG:3857',
format: new ol.format.GeoJSON()
}),