This topic describes the ST_Generalize function. This function aggregates a geographic grid from a high level to a low level.
Syntax
geomgrid ST_Generalize(geomgrid gridcode, integer precision);
geomgrid[] ST_Generalize(geomgrid[] gridarray, integer precision, bool degenerated default false);Parameters
Parameter | Description |
gridcode | The geographic grid object. |
gridarray | The array of geographic grids. |
precision | The aggregation level. |
degenerated | Specifies whether to use a degenerated grid. |
Description
This function aggregates a geographic grid or an array of geographic grids to a low level.
Examples
SELECT ST_AsText(ST_Generalize(ST_GridFromText('GZ0026206440'), 5));
st_astext
-----------
GZ00262
SELECT ST_Generalize(ST_As3DGrid(
'srid=4490;LINESTRING Z (116 39 2000,116.012 39.009 3000)'::geometry, 10), 8);
st_generalize
---------------------------------------------
{01024008722600000000,01024008742600000000}