Create a heatmap layer | NMaps GL JS Docs

Visualize earthquake frequency by location using a heatmap layer.
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title>Create a heatmap layer</title>
<meta name="viewport" content="initial-scale=1,maximum-scale=1,user-scalable=no" />
<script src="https://cdn.ndrive.com/nmapsgl/v.1.6.8/nmaps-gl.js"></script>
<link href="https://cdn.ndrive.com/nmapsgl/v.1.6.8/nmaps-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>
	// TO MAKE THE MAP APPEAR YOU MUST ADD YOUR ACCESS TOKEN
	nmapsgl.accessToken = '<your access token here>';
	
const map = new nmapsgl.Map({
container: 'map',
style: 'Dark',
center: [-120, 50],
zoom: 2
});
 
map.on('load', () => {
// Add a geojson point source.
// Heatmap layers also work with a vector tile source.
map.addSource('earthquakes', {
'type': 'geojson',
'data': 'https://nmaps-gl.ndrive.com/nmaps-gl-js/assets/earthquakes.geojson'
});
 
map.addLayer({
'id': 'earthquakes-heat',
'type': 'heatmap',
'source': 'earthquakes',
'maxzoom': 9,
'paint': {
// Increase the heatmap weight based on frequency and property magnitude
'heatmap-weight': [
'interpolate',
['linear'],
['get', 'mag'],
0,
0,
6,
1
],
// Increase the heatmap color weight weight by zoom level
// heatmap-intensity is a multiplier on top of heatmap-weight
'heatmap-intensity': [
'interpolate',
['linear'],
['zoom'],
0,
1,
9,
3
],
// Color ramp for heatmap.  Domain is 0 (low) to 1 (high).
// Begin color ramp at 0-stop with a 0-transparancy color
// to create a blur-like effect.
'heatmap-color': [
'interpolate',
['linear'],
['heatmap-density'],
0,
'rgba(33,102,172,0)',
0.2,
'rgb(103,169,207)',
0.4,
'rgb(209,229,240)',
0.6,
'rgb(253,219,199)',
0.8,
'rgb(239,138,98)',
1,
'rgb(178,24,43)'
],
// Adjust the heatmap radius by zoom level
'heatmap-radius': [
'interpolate',
['linear'],
['zoom'],
0,
2,
9,
20
],
// Transition from heatmap to circle layer by zoom level
'heatmap-opacity': [
'interpolate',
['linear'],
['zoom'],
7,
1,
9,
0
]
}
});
 
map.addLayer({
'id': 'earthquakes-point',
'type': 'circle',
'source': 'earthquakes',
'minzoom': 7,
'paint': {
// Size circle radius by earthquake magnitude and zoom level
'circle-radius': [
'interpolate',
['linear'],
['zoom'],
7,
['interpolate', ['linear'], ['get', 'mag'], 1, 1, 6, 4],
16,
['interpolate', ['linear'], ['get', 'mag'], 1, 5, 6, 50]
],
// Color circle by earthquake magnitude
'circle-color': [
'interpolate',
['linear'],
['get', 'mag'],
1,
'rgba(33,102,172,0)',
2,
'rgb(103,169,207)',
3,
'rgb(209,229,240)',
4,
'rgb(253,219,199)',
5,
'rgb(239,138,98)',
6,
'rgb(178,24,43)'
],
'circle-stroke-color': 'white',
'circle-stroke-width': 1,
// Transition from heatmap to circle layer by zoom level
'circle-opacity': [
'interpolate',
['linear'],
['zoom'],
7,
0,
8,
1
]
}
});
});
</script>
 
</body>
</html>