OpenLayers示例代码：地震热图
OpenLayers示例代码：地震热图
<!DOCTYPE html>
<html>
<head>
<title>Earthquakes Heatmap</title>
<link rel="stylesheet" href="https://openlayers.org/en/v4.0.1/css/ol.css" type="text/css">
<!-- The line below is only needed for old environments like Internet Explorer and Android 4.x -->
<script src="https://cdn.polyfill.io/v2/polyfill.min.js?features=requestAnimationFrame,Element.prototype.classList,URL"></script>
<script src="https://openlayers.org/en/v4.0.1/build/ol.js"></script>
</head>
<body>
<div id="map" class="map"></div>
<form>
<label>radius size</label>
<input id="radius" type="range" min="1" max="50" step="1" value="5"/>
<label>blur size</label>
<input id="blur" type="range" min="1" max="50" step="1" value="15"/>
</form>
<script>
var blur = document.getElementById('blur');
var radius = document.getElementById('radius');
var vector = new ol.layer.Heatmap({
source: new ol.source.Vector({
url: 'https://openlayers.org/en/v4.0.1/examples/data/kml/2012_Earthquakes_Mag5.kml',
format: new ol.format.KML({
extractStyles: false
})
}),
blur: parseInt(blur.value, 10),
radius: parseInt(radius.value, 10)
});
vector.getSource().on('addfeature', function(event) {
// 2012_Earthquakes_Mag5.kml stores the magnitude of each earthquake in a
// standards-violating <magnitude> tag in each Placemark. We extract it from
// the Placemark's name instead.
var name = event.feature.get('name');
var magnitude = parseFloat(name.substr(2));
event.feature.set('weight', magnitude - 5);
});
var raster = new ol.layer.Tile({
source: new ol.source.Stamen({
layer: 'toner'
})
});
var map = new ol.Map({
layers: [raster, vector],
target: 'map',
view: new ol.View({
center: [0, 0],
zoom: 2
})
});
blur.addEventListener('input', function() {
vector.setBlur(parseInt(blur.value, 10));
});
radius.addEventListener('input', function() {
vector.setRadius(parseInt(radius.value, 10));
});
</script>
</body>
</html>
说明：
OpenLayers示例代码：地震热图
