geojson-geometries-lookup

⚡️ Fast geometry in geometry lookup for large GeoJSONs.
_{Coded with ❤️ by Simone Primarosa.}

Synopsis

With this package you can perform the following operations (and more) on a given GeoJSON.

• Given a Point get all the Points in the GeoJSON that intersects it.
• Given a Point get all the Lines in the GeoJSON that intersects it.
• Given a Point get all the Polygons in the GeoJSON that contains it.
• Given a Line get all the Lines in the GeoJSON that contains it.
• Given a Line get all the Polygons in the GeoJSON that contains it.
• Given a Polygon get all the Polygons in the GeoJSON that contains it.

Install

$ npm install --save geojson-geometries-lookup

Showcase

Do you use geojson-geometries-lookup in your application? Please open a Pull Request to include it here.
We would love to have it in our list:

• country-iso: 🗺 Get ISO 3166-1 alpha-3 country code for geographic coordinates.
• is-sea: 🌊 Check whether a geographic coordinate is in the sea or not on the earth.

Usage

const GeoJsonGeometriesLookup = require('geojson-geometries-lookup');

const geojson = {type: 'FeatureCollection',
  features: [{
    type: 'Feature',
    geometry: {
      type: 'Point',
      coordinates: [102.0, 0.5]
    },
    properties: {prop0: 'value0'}
  }, {
    type: 'Feature',
    geometry: {
      type: 'LineString',
      coordinates: [[100.0, 0.0], [101.0, 0.0], [101.0, 1.0], [100.0, 1.0]]
    },
    properties: {prop1: 'value1'}
  }, {
    type: 'Feature',
    geometry: {
      type: 'Polygon',
      coordinates: [
        [[100.0, 0.0], [101.0, 0.0], [101.0, 1.0], [100.0, 1.0], [100.0, 0.0]]
      ]
    },
    properties: {prop2: 'value2'}
  }]
};

const glookup = new GeoJsonGeometriesLookup(geojson);

const point1 = {type: "Point", coordinates: [102.0, 0.5]};
glookup.getContainers(point1);
// => {
//   type: 'FeatureCollection',
//   features: [{
//     type: 'Feature',
//     geometry: {
//       type: 'Point',
//       coordinates: [102.0, 0.5]
//     },
//     properties: {prop0: 'value0'}
//   }]
// }
glookup.countContainers(point1);
// => 1

glookup.getContainers(point1, {ignorePoints: true});
// => {
//   type: 'FeatureCollection',
//   features: []
// }
glookup.countContainers(point1, {ignorePoints: true});
// => 0

const point2 = {type: "Point", coordinates: [101.0, 0.0]};
glookup.getContainers(point2);
// => {
//   type: 'FeatureCollection',
//   features: [{
//     type: 'Feature',
//     geometry: {
//       type: 'LineString',
//       coordinates: [[100.0, 0.0], [101.0, 0.0], [101.0, 1.0], [100.0, 1.0]]
//     },
//     properties: {prop1: 'value1'}
//   }, {
//     type: 'Feature',
//     geometry: {
//       type: 'Polygon',
//       coordinates: [
//         [[100.0, 0.0], [101.0, 0.0], [101.0, 1.0], [100.0, 1.0], [100.0, 0.0]]
//       ]
//     },
//     properties: {prop2: 'value2'}
//   }]
// }
glookup.getContainers(point2, {ignorePolygons: true});
// => {
//   type: 'FeatureCollection',
//   features: [{
//     type: 'Feature',
//     geometry: {
//       type: 'LineString',
//       coordinates: [[100.0, 0.0], [101.0, 0.0], [101.0, 1.0], [100.0, 1.0]]
//     },
//     properties: {prop1: 'value1'}
//   }]
// }
glookup.hasContainers(point1, {ignorePoints: true, ignoreLines: true});
// => true

const poly1 = {
  type: 'Polygon',
  coordinates: [
    [[100.0+0.25, 0.0+0.25], [101.0-0.25, 0.0+0.25], [101.0-0.25, 1.0-0.25], [100.0+0.25, 1.0-0.25], [100.0+0.25, 0.0+0.25]]
  ]
}
glookup.getContainers(poly1, {ignorePoints: true, ignoreLines: true});
// => {
//   type: 'FeatureCollection',
//   features: [{
//     type: 'Feature',
//     geometry: {
//       type: 'Polygon',
//       coordinates: [
//         [[100.0, 0.0], [101.0, 0.0], [101.0, 1.0], [100.0, 1.0], [100.0, 0.0]]
//       ]
//     },
//     properties: {prop2: 'value2'}
//   }]
// }

API

new GeoJsonGeometriesLookup(geoJson, [options])

Create an instance of the GeoJSON lookup class.

geoJsonGeometriesLookup.forEachContainer(geometry, [options]) ⇒ number

Iterate on each geometry that completely contains the geometry provided.

Kind: instance method of GeoJsonGeometriesLookup
Returns: number - The number of geometries that completely contains the geometry provided iterated. The interiors of both geometries must intersect and, the interior and boundary of the secondary (geometry b) must not intersect the exterior of the primary (geometry a).

geoJsonGeometriesLookup.getContainers(geometry, [options]) ⇒ Object

Gets the geometries that completely contains the geometry provided.

Kind: instance method of GeoJsonGeometriesLookup
Returns: Object - A FatureCollection of geometries that completely contains the geometry provided. The interiors of both geometries must intersect and, the interior and boundary of the secondary (geometry b) must not intersect the exterior of the primary (geometry a).

geoJsonGeometriesLookup.hasContainers(geometry, [options]) ⇒ boolean

Checks if there is at least one geometry that completely contains the geometry provided.

Kind: instance method of GeoJsonGeometriesLookup
Returns: boolean - True if there is at least one geometry that completely contains the geometry provided. The interiors of both geometries must intersect and, the interior and boundary of the secondary (geometry b) must not intersect the exterior of the primary (geometry a).

geoJsonGeometriesLookup.countContainers(geometry, [options]) ⇒ number

Counts the number of geometries that completely contains the geometry provided.

Kind: instance method of GeoJsonGeometriesLookup
Returns: number - The number of geometries that completely contains the geometry provided. The interiors of both geometries must intersect and, the interior and boundary of the secondary (geometry b) must not intersect the exterior of the primary (geometry a).

Contributing

Contributions are REALLY welcome and if you find a security flaw in this code, PLEASE report it.

Authors

• Simone Primarosa - Github (@simonepri) • Twitter (@simoneprimarosa)

See also the list of contributors who participated in this project.

License

This project is licensed under the MIT License - see the license file for details.