s2

Our S2 module is based on a port of the official S2 geometry library created by Google. For more information about S2 check the library's website or the Spatial Indexes section of this documentation.

S2_BOUNDARY

S2_BOUNDARY(id)

Description

Returns the boundary for a given S2 cell ID. We extract the boundary by getting the corner longitudes and latitudes, then enclose it in a GeoJSON and finally transform it into geography.

• id: BIGINT S2 cell ID to get the boundary geography from.

Return type

GEOGRAPHY

Example

SELECT CARTO.CARTO.S2_BOUNDARY(955378847514099712);
-- { "coordinates": [ [ [ -3.743508991266907, 40.24850114133136 ], [ -3.743508991266907, 40.57421345060903 ] ...

S2 Cell edges are spherical geodesics.

S2_FROMGEOGPOINT

S2_FROMGEOGPOINT(point, resolution)

Description

Returns the S2 cell ID of a given point at a requested resolution.

• point: GEOGRAPHY point to get the ID from.

• resolution: INT level of detail or zoom.

Return type

BIGINT

Example

SELECT CARTO.CARTO.S2_FROMGEOGPOINT(ST_POINT(-3.7038, 40.4168), 8);
-- 955378847514099712

S2_FROMHILBERTQUADKEY

S2_FROMHILBERTQUADKEY(hquadkey)

Description

Returns the conversion of a Hilbert quadkey (a.k.a Hilbert curve quadtree ID) into a S2 cell ID.

• hquadkey: STRING Hilbert quadkey to be converted.

Return type

BIGINT

Example

SELECT CARTO.CARTO.S2_FROMHILBERTQUADKEY('0/12220101');
-- 955378847514099712

S2_FROMLONGLAT

S2_FROMLONGLAT(longitude, latitude, resolution)

Description

Returns the S2 cell ID for a given longitude, latitude and zoom resolution.

• longitude: DOUBLE horizontal coordinate on the map.

• latitude: DOUBLE vertical coordinate on the map.

• resolution: INT level of detail or zoom.

Return type

BIGINT

Example

SELECT CARTO.CARTO.S2_FROMLONGLAT(-3.7038, 40.4168, 8);
-- 955378847514099712

S2_TOHILBERTQUADKEY

S2_TOHILBERTQUADKEY(id)

Description

Returns the conversion of a S2 cell ID into a Hilbert quadkey (a.k.a Hilbert curve quadtree ID).

• id: BIGINT S2 cell ID to be converted.

Return type

STRING

Example

SELECT CARTO.CARTO.S2_TOHILBERTQUADKEY(955378847514099712);
-- 0/12220101