Class: GeojsonFlatbush

GeojsonFlatbush(numItems, nodeSizeopt, ArrayTypeopt) → {GeojsonFlatbush}

new GeojsonFlatbush(numItems, nodeSizeopt, ArrayTypeopt) → {GeojsonFlatbush}

Instantiates a GeojsonFlatbush index.
Parameters:
Name Type Attributes Default Description
numItems Number Number of items to store in static index.
nodeSize Number <optional>
 16 Size of the tree node.
ArrayType Number <optional>
 Float64Array Array type coordinate storage.
Source:
Returns:
New instance of GeojsonFlatbush.
Type
GeojsonFlatbush
Example
// Initialize GeojsonFlatbush for 1000 items.
const index = new GeojsonFlatbush(1000)

Members

index :Flatbush

Flatbush spatial index.
Type:
  • Flatbush
Source:

Methods

(static) from(data) → {GeojsonFlatbush}

Instantiates a GeojsonFlatbush index from raw 'data' member.
Parameters:
Name Type Description
data ArrayBuffer Raw indexing data array.
Source:
Returns:
New instance of GeojsonFlatbush.
Type
GeojsonFlatbush
Example
// Reconstruct the index from a raw array buffer.
const index = GeojsonFlatbush.from(e.index.data);

add(data)

Adds a single GeoJSON to the index.
Parameters:
Name Type Description
data GeoJSON | Array GeoJSON or bounding box array.
Source:
Example
// Fill the index with a line string.
const line = turf.lineString([[0, 0], [1, 1]]);
index.add(line);

finish()

Performs indexing of the added GeoJSON.
Source:
Example
// Perform the indexing. Should only be called once when done adding data.
index.finish()

load(data)

Bulk load a collection to the index.
Parameters:
Name Type Description
data FeatureCollection | Array GeoJSON or array of features/bboxes.
Source:
Example
// Fill the index with a feature collection.
const collection = turf.featureCollection([
  turf.lineString([[0, 0], [1, 1]]),
  turf.lineString([[0, 1], [1, 2]]),
]);
index.load(collection);

neighbors(point, maxResultsopt, maxDistanceopt, collectionopt, filterFnopt) → {FeatureCollection|Array}

Finds the K nearest neighbors from a point.
Parameters:
Name Type Attributes Default Description
point point Query point.
maxResults Number <optional>
 Infinity Maximum number of results (= K).
maxDistance Number <optional>
 Infinity Maximum distance from point allowed.
collection GeoJSON <optional>
 null Source collection to select items from.
filterFn function <optional>
 Called on every found item (passing an item index) and only includes it if function returned a truthy value.
Source:
Returns:
Features found or their IDs.
Type
FeatureCollection | Array
Example
// Find the 5 nearest neighbors.
const point = turf.point([0,0]);
const neighbors = index.neighbors(point, 5, Infinity, collection);
Find items in the bounding box of the GeoJSON.
Parameters:
Name Type Attributes Description
geojson GeoJSON | Array GeoJSON or its bounding box.
collection GeoJSON <optional>
 Source collection from which to return items.
filterFn function <optional>
 Called on every found item (passing an item index) and only includes it if the function returned a truthy value.
Source:
Returns:
IDs or features found.
Type
Array | FeatureCollection
Example
// Make a GeoJSON query.
const polygon = turf.polygon([[[0, 0], [1, 0], [1, 1], [0, 1], [0, 0]]]);
const found = index.search(polygon, collection);