strTreeIndex

Constructs a 2D R-tree spatial index using Sort-Tile-Recursive (STR) packing algorithm.

The index is query-only; once constructed, geometries cannot be added or removed from the index.

The tree indexes the bounding boxes of each geometry. Geometries of any type can be indexed, types can mix within one index. Empty geometries are ignored during indexing and will never be returned by queries.

Type Parameters

• G - The type of indexed geometry

Parameters

Name	Type	Default	Description
geometries	G[]		The array of geometries to be indexed
options?	object		Optional options object
options.nodeCapacity?	number	10	The maximum number of child nodes that a tree node may have. The minimum recommended capacity value is 4.

Returns

STRTreeRef<G>

A new STRTreeRef instance

Throws

• GEOSError when options.nodeCapacity is less than 2

Examples

const geometriesToIndex = [
    point([ 0, 0 ]), point([ 0, 2 ]), point([ 0, 4 ]),
    point([ 2, 0 ]), point([ 2, 2 ]), point([ 2, 4 ]),
    point([ 4, 0 ]), point([ 4, 2 ]), point([ 4, 4 ]),
    point([ 6, 0 ]), lineString([ [ 6, 2 ], [ 6, 4 ] ]),
];
const tree = strTreeIndex(geometriesToIndex);

// index can now be queried by geometry bbox:
const g1 = box([ 3, 1, 7, 3 ]); // <POLYGON ((3 1, 3 3, 7 3, 7 1, 3 1))>
// note that not the geometry but just its bbox will be used by the query
// any geometry type could be used to query index, including points and lines
const queryMatches = tree.query(g1);
// [ <POINT (4 2)>, <LINESTRING (6 2, 6 4)> ]

// or used to find the nearest tree geometry:
const g2 = point([ 1.5, 1.75 ]);
// `nearest` uses Cartesian distance not between bboxes but actual geometries
const nearestMatch = tree.nearest(g2);
// <POINT (2 2)>

const geometriesToIndex = [ point([ 0, 0 ]), point([ 0, 2 ]), point([ 0, 4 ]), point([ 2, 0 ]), point([ 2, 2 ]), point([ 2, 4 ]), point([ 4, 0 ]), point([ 4, 2 ]), point([ 4, 4 ]), point([ 6, 0 ]), lineString([ [ 6, 2 ], [ 6, 4 ] ]), ]; const tree = strTreeIndex(geometriesToIndex); // index can now be queried by geometry bbox: const g1 = box([ 3, 1, 7, 3 ]); // <POLYGON ((3 1, 3 3, 7 3, 7 1, 3 1))> // note that not the geometry but just its bbox will be used by the query // any geometry type could be used to query index, including points and lines const queryMatches = tree.query(g1); // [ <POINT (4 2)>, <LINESTRING (6 2, 6 4)> ] // or used to find the nearest tree geometry: const g2 = point([ 1.5, 1.75 ]); // `nearest` uses Cartesian distance not between bboxes but actual geometries const nearestMatch = tree.nearest(g2); // <POINT (2 2)>