mapbox创建集群和样式设置

使用Mapbox GL JS的内置函数将点可视化为群集，并对集群的样式进行设置，具体代码如下：

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<!DOCTYPE html>
<html>

<head>
<meta charset="utf-8" />
<title>Create and style clusters</title>
<meta name="viewport" content="initial-scale=1,maximum-scale=1,user-scalable=no" />
<script src="//i2.wp.com/api.mapbox.com/mapbox-gl-js/v1.12.0/mapbox-gl.js"></script>
<link href="https://api.mapbox.com/mapbox-gl-js/v1.12.0/mapbox-gl.css" rel="stylesheet" />
<style>
body {
margin: 0;
padding: 0;
}

#map {
position: absolute;
top: 0;
bottom: 0;
width: 100%;
}

</style>
</head>

<body>
<div id="map"></div>

<script>
mapboxgl.accessToken = 'pk.eyJ1IjoiaHpzejIwMjAiLCJhIjoiY2tjdm9kdGFqMDYyODJ5czRsYnk4aDVscCJ9.DryU0-YwREpTBZ5qKXSqUQ';
var map = new mapboxgl.Map({
container: 'map',
style: 'mapbox://styles/mapbox/dark-v10',
center: [-103.59179687498357, 40.66995747013945],
zoom: 3
});

map.on('load', function () {
// Add a new source from our GeoJSON data and
// set the 'cluster' option to true. GL-JS will
// add the point_count property to your source data.
map.addSource('earthquakes', {
type: 'geojson',
// Point to GeoJSON data. This example visualizes all M1.0+ earthquakes
// from 12/22/15 to 1/21/16 as logged by USGS' Earthquake hazards program.
data: 'https://docs.mapbox.com/mapbox-gl-js/assets/earthquakes.geojson',
cluster: true,
clusterMaxZoom: 14, // Max zoom to cluster points on
clusterRadius: 50 // Radius of each cluster when clustering points (defaults to 50)
});

map.addLayer({
id: 'clusters',
type: 'circle',
source: 'earthquakes',
filter: ['has', 'point_count'],
paint: {
// Use step expressions (https://docs.mapbox.com/mapbox-gl-js/style-spec/#expressions-step)
// with three steps to implement three types of circles:
// * Blue, 20px circles when point count is less than 100
// * Yellow, 30px circles when point count is between 100 and 750
// * Pink, 40px circles when point count is greater than or equal to 750
'circle-color': [
'step',
['get', 'point_count'],
'#51bbd6',
100,
'#f1f075',
750,
'#f28cb1'
],
'circle-radius': [
'step',
['get', 'point_count'],
20,
100,
30,
750,
40
],
"circle-stroke-color": [
"step",
["get", "point_count"],
"rgba(81, 187, 214, 0.2)",
100,
"rgba(241, 240, 117, 0.2)",
750,
"rgba(242, 140, 177, 0.2)"
],
// 这个是外边框晕染的范围
"circle-stroke-width": [
"step",
["get", "point_count"],
10, //蓝色晕染长度，当点数小于100时为5px晕染
100, //对应上面circle-color 数字，意思为100以内
20, //点计数在100到750之间时为黄色，6px晕染
750, //对应上面circle-color 数字，意思为750以内
30 //点计数大于或等于750时为7px像素的粉红色晕染
]
}
});

map.addLayer({
id: 'cluster-count',
type: 'symbol',
source: 'earthquakes',
filter: ['has', 'point_count'],
layout: {
// 'text-field': '{point_count_abbreviated}',
'text-field': '{point_count}',

'text-font': ['DIN Offc Pro Medium', 'Arial Unicode MS Bold'],
'text-size': 12
}
});

map.addLayer({
id: 'unclustered-point',
type: 'circle',
source: 'earthquakes',
filter: ['!', ['has', 'point_count']],
paint: {
'circle-color': '#11b4da',
'circle-radius': 4,
'circle-stroke-width': 1,
'circle-stroke-color': '#fff'
}
});

// inspect a cluster on click
map.on('click', 'clusters', function (e) {
var features = map.queryRenderedFeatures(e.point, {
layers: ['clusters']
});
var clusterId = features[0].properties.cluster_id;
map.getSource('earthquakes').getClusterExpansionZoom(
clusterId,
function (err, zoom) {
if (err) return;

map.easeTo({
center: features[0].geometry.coordinates,
zoom: zoom
});
}
);
});

// When a click event occurs on a feature in
// the unclustered-point layer, open a popup at
// the location of the feature, with
// description HTML from its properties.
map.on('click', 'unclustered-point', function (e) {
var coordinates = e.features[0].geometry.coordinates.slice();
var mag = e.features[0].properties.mag;
var tsunami;

if (e.features[0].properties.tsunami === 1) {
tsunami = 'yes';
} else {
tsunami = 'no';
}

// Ensure that if the map is zoomed out such that
// multiple copies of the feature are visible, the
// popup appears over the copy being pointed to.
while (Math.abs(e.lngLat.lng - coordinates[0]) > 180) {
coordinates[0] += e.lngLat.lng > coordinates[0] ? 360 : -360;
}

new mapboxgl.Popup()
.setLngLat(coordinates)
.setHTML(
'magnitude: ' + mag + '<br>Was there a tsunami?: ' + tsunami
)
.addTo(map);
});

map.on('mouseenter', 'clusters', function () {
map.getCanvas().style.cursor = 'pointer';
});
map.on('mouseleave', 'clusters', function () {
map.getCanvas().style.cursor = '';
});
});

</script>

</body>

</html>

实现效果如下：

期待与大家一起交流学习！！