Files
openlayers/examples/heatmap-earthquakes.js
Olivier Guyot 80b4473180 Simplify the heatmap example
Use a weight function instead of manually edditing the features.
2019-10-28 10:27:29 +01:00

56 lines
1.5 KiB
JavaScript

import Map from '../src/ol/Map.js';
import View from '../src/ol/View.js';
import KML from '../src/ol/format/KML.js';
import {Heatmap as HeatmapLayer, Tile as TileLayer} from '../src/ol/layer.js';
import Stamen from '../src/ol/source/Stamen.js';
import VectorSource from '../src/ol/source/Vector.js';
const blur = document.getElementById('blur');
const radius = document.getElementById('radius');
const vector = new HeatmapLayer({
source: new VectorSource({
url: 'data/kml/2012_Earthquakes_Mag5.kml',
format: new KML({
extractStyles: false
})
}),
blur: parseInt(blur.value, 10),
radius: parseInt(radius.value, 10),
weight: function(feature) {
// 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.
const name = feature.get('name');
const magnitude = parseFloat(name.substr(2));
return magnitude - 5;
}
});
const raster = new TileLayer({
source: new Stamen({
layer: 'toner'
})
});
new Map({
layers: [raster, vector],
target: 'map',
view: new View({
center: [0, 0],
zoom: 2
})
});
const blurHandler = function() {
vector.setBlur(parseInt(blur.value, 10));
};
blur.addEventListener('input', blurHandler);
blur.addEventListener('change', blurHandler);
const radiusHandler = function() {
vector.setRadius(parseInt(radius.value, 10));
};
radius.addEventListener('input', radiusHandler);
radius.addEventListener('change', radiusHandler);