Reputation: 99
I am working with react-native-mapbox-gl. I have an array of locations which I am looping through to draw markers on the map. But there are some locations which are very closer to each other and are nearly not visible. I want to cluster all the locations which are near to each other so that when I click on it, it expands and show me all the locations which are into that cluster.
There is <MapboxGL.ShapeSource />
available in mapbox but it asks for a url in which lat long are to be loaded from. But I have an array with lat long of each location. Is there any other way I can make a cluster of locations in mapbox.
<Mapbox.MapView
styleURL={Mapbox.StyleURL.Dark}
zoomLevel={15}
centerCoordinate={[locations[0].longitude, locations[0].latitude]}
style={styles.container}
showUserLocation={true}>
{this.renderLocations(locations)}
</Mapbox.MapView>
render location function loops through the location array and shows markers on the map
renderLocations(locations) {
return locations.map((loc, locIndex) => {
return (
<Mapbox.PointAnnotation
key={`${locIndex}pointAnnotation`}
id={`${locIndex}pointAnnotation`}
coordinate={[loc.longitude, loc.latitude]}
title={loc.name}>
<Image source={require("../../../assets/images/marker.png")}/>
<Mapbox.Callout title={loc.name} />
</Mapbox.PointAnnotation>
);
});
Upvotes: 3
Views: 1505
Reputation: 591
You can use @turf/clusterDbScan like this :
let collection = MapboxGL.geoUtils.makeFeatureCollection();
results.forEach(result => {
const geometry = {
type: "Point",
coordinates: [result.lon, result.lat]
};
let marker = MapboxGL.geoUtils.makeFeature(geometry);
marker.id = result.id
marker.properties = {
...yourProperties
};
collection = MapboxGL.geoUtils.addToFeatureCollection(collection, marker);
});
// Let Turf do the job !
const maxDistance = 0.005;
const clustered = turf.clustersDbscan(collection, maxDistance);
// Markers have no cluster property
const markers = clustered.features
.filter( f => f.properties.cluster===undefined)
.map(f => {
return {...f.properties, coordinates: f.geometry.coordinates}
})
// Clusters have one (cluster id)
let clusters = {};
clustered.features
.filter( f => f.properties.cluster!==undefined)
.forEach( f => {
const { cluster, id} = f.properties;
const { coordinates } = f.geometry;
if (!clusters[cluster]) {
clusters[cluster] = {
id: `cluster_${cluster}`,
count: 1,
objects: [id],
coordinates: coordinates
}
console.tron.log({clusters})
}
else {
const { count } = clusters[cluster]
const [lastX, lastY] = clusters[cluster].coordinates;
const [x, y] = coordinates;
const newX = ((lastX * count) + x) / (count+1);
const newY = ((lastY * count) + y) / (count+1);
clusters[cluster] = {
...clusters[cluster],
count: count+1,
objects: [...clusters[cluster].objects, id],
coordinates: [newX, newY]
}
}
})
this.setState({ markers, clusters: _.values(clusters) });
Upvotes: 2