geojson-network-parser
v0.1.3
Published
A utility that turns a GeoJSON FeatureCollection of a road network and turns it into a routable graph
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Readme
A utility that turns a GeoJSON FeatureCollection of a road network and turns it into a routable graph
Installation
npm install geojson-network-parser
Usage
const NetworkParser = require('geojson-network-parser');
var geojson = {
type: 'FeatureCollection',
features: [
{
type: 'Feature',
properties: {
layer: 'roadway',
cost: 4
},
geometry: {
type: 'LineString',
geometry: [[-37.231312, 32.4444], [-37.23111, 32.5534] /* and so on ... */ ]
}
},
// ... and so on with more roads
]
};
// Filter the features only process the ones that represent roads
const roads = geojson.features.filter(f => (f.properties.layer === "roadway"));
// Turn the GeoJSON FeatureCollection of roads into a network that we can find shortest-path routes on
const network = new NetworkParser(roads, "cost", 2);
const parsed = network.parse({
tolerance: 0.0000075, // Ignore gaps greater than this distance. Units are in degrees latitude, so values < 0.00002 are a good starting point.
ignoreCrossings: false // If `true`, intersections will only be added where there are two nearby points in the original FeatureCollection. If `false`, intersections will be inferred where two edge segments cross each other.
});
// Snap latitude/longitude point to nearest node on the network
const A = network.getNearestNode([-37.231312, 32.4444]);
const B = network.getNearestNode([-37.23111, 32.5534]);
// Get a list of nodes that connect the shortest path between two points
const route = network.findShortestPath(A, B);
Building from source
Clone this repo then run:
npm install
npm run build
This will output a bundled js file to dist/geojson-network-parser.js
.