This topic describes the ST_AsH3Grid function. This function converts a 2D geometry object into an H3 grid representation.
Syntax
h3grid[] ST_AsH3Grid(geometry geom, integer precision, bool degenerated default false);Parameters
Parameter | Description |
geom | The geometry object. |
precision | The precision level. Valid values: 0 to 15. |
degenerated | Specifies whether to use a degenerated grid. |
Description
Degenerated grids work in the same way as H3.
The SRID can be any projection. This function automatically converts the projection.
Examples
-- POINT
select ST_AsH3Grid(st_geomfromtext('POINT(2932234 234234)',28992),4);
st_ash3grid
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{010101FFFFFFFF09D54208}
--LINESTRING
select st_ash3grid('SRID=4326;LINESTRING(122.48077 51.72814,122.47416 51.73714)'::geometry, 10);
st_ash3grid
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{010100FFFF59698658A108,010100FF7F58698658A108,010100FFFF5A698658A108,010100FF7F51698658A108,010100FF7F50698658A108,010100FF7F52698658A108,010100FF7FCD698658A108,010100FF7FCF698658A108,010100FF7FCE698658A108,010100FFFFC0698658A108,010100FF7FC7698658A108,010100FFFFD5698658A108}
(1 row)
-- MULTIPOLYGON
SELECT ST_AsH3Grid('SRID=4326;MULTIPOLYGON(((0 0,10 0,10 10,0 10,0 0),(2 2,2 5,5 5,5 2,2 2))) '::geometry, 2);
st_ash3grid
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{010100FFFFFFFF7F882508,010100FFFFFFFF7F2C2808,010100FFFFFFFF7F2D2808,010100FFFFFFFF7F8B2508,010100FFFFFFFF7F2F2808,010100FFFFFFFF7F8D2508,010100FFFFFFFF7F892508,010100FFFFFFFF7F8F2508,010100FFFFFFFF7F542708,010100FFFFFFFF7F572708,010100FFFFFFFFFF882508,010100FFFFFFFFFF892508,010100FFFFFFFFFF2D2808,010100FFFFFFFFFF2E2808,010100FFFFFFFFFF8A2508,010100FFFFFFFFFF5708}
(1 row)