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Layers (32)
Display buildings in 3DExtrude polygons for 3D indoor mappingAdd a 3D modelAdjust a layer's opacityAnimate a lineAnimate a series of imagesAnimate a pointChange building color based on zoom levelChange the case of labelsDisplay HTML clusters with custom propertiesCreate and style clustersChange a layer's color with buttonsAdd a custom style layerStyle circles with a data-driven propertyStyle lines with a data-driven propertyDisplay and style rich text labelsUse a fallback imageAdd a pattern to a polygonAdd a new layer below labelsAdd a GeoJSON lineDraw GeoJSON pointsAdd a GeoJSON polygonAdd hillshadingCreate a gradient line using an expressionAdd multiple geometries from one GeoJSON sourceStyle ocean depth dataShow and hide layersChange worldview of administrative boundariesUpdate a choropleth layer by zoom levelVariable label placementVisualize population densityCreate a heatmap layer

Visualize population density

Using a variable binding expression to calculate and display population density.

<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title>Visualize population density</title>
<meta name="viewport" content="initial-scale=1,maximum-scale=1,user-scalable=no" />
<script src="https://api.tiles.mapbox.com/mapbox-gl-js/v1.6.0/mapbox-gl.js"></script>
<link href="https://api.tiles.mapbox.com/mapbox-gl-js/v1.6.0/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 = '<your access token here>';
var map = new mapboxgl.Map({
container: 'map', // container id
style: 'mapbox://styles/mapbox/streets-v11', // stylesheet location
center: [30.0222, -1.9596], // starting position [lng, lat]
zoom: 7 // starting zoom
});
map.on('load', function() {
map.addLayer({
'id': 'rwanda-provinces',
'type': 'fill',
'source': {
'type': 'geojson',
'data':
'https://docs.mapbox.com/mapbox-gl-js/assets/rwanda-provinces.geojson'
},
'layout': {},
'paint': {
'fill-color': [
'let',
'density',
['/', ['get', 'population'], ['get', 'sq-km']],
[
'interpolate',
['linear'],
['zoom'],
8,
[
'interpolate',
['linear'],
['var', 'density'],
274,
['to-color', '#edf8e9'],
1551,
['to-color', '#006d2c']
],
10,
[
'interpolate',
['linear'],
['var', 'density'],
274,
['to-color', '#eff3ff'],
1551,
['to-color', '#08519c']
]
]
],
'fill-opacity': 0.7
}
});
});
</script>
</body>
</html>
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