Categories:: Geospatial functions

ST_YMAX¶

Returns the maximum latitude (Y coordinate) of all points contained in the specified GEOGRAPHY or GEOMETRY object.

Syntax¶

ST_YMAX( <geography_or_geometry_expression> ) 

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Arguments¶

geography_or_geometry_expression: The argument must be an expression of type GEOGRAPHY or GEOMETRY.

Returns¶

Returns a REAL value.

Usage notes¶

The function takes into account the curvature of the edges toward the poles.

Examples¶

GEOGRAPHY examples¶

This shows a simple use of the ST_XMIN, ST_XMAX, ST_YMIN, and ST_YMAX functions:

CREATE or replace TABLE extreme_point_collection (id INTEGER, g GEOGRAPHY); INSERT INTO extreme_point_collection (id, g) SELECT column1, TO_GEOGRAPHY(column2) FROM VALUES (1, 'POINT(-180 0)'), (2, 'POINT(180 0)'), (3, 'LINESTRING(-179 0, 179 0)'), (4, 'LINESTRING(-60 30, 60 30)'), (5, 'LINESTRING(-60 -30, 60 -30)'); 

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SELECT g, ST_XMIN(g), ST_XMAX(g), ST_YMIN(g), ST_YMAX(g) FROM extreme_point_collection ORDER BY id; +----------------------------+------------+------------+-------------------+-------------------+ | G | ST_XMIN(G) | ST_XMAX(G) | ST_YMIN(G) | ST_YMAX(G) | |----------------------------+------------+------------+-------------------+-------------------| | POINT(-180 0) | -180 | 180 | 0 | 0 | | POINT(180 0) | -180 | 180 | 0 | 0 | | LINESTRING(-179 0,179 0) | -180 | 180 | -6.883275617e-14 | 6.883275617e-14 | | LINESTRING(-60 30,60 30) | -60 | 60 | 30 | 49.106605351 | | LINESTRING(-60 -30,60 -30) | -60 | 60 | -49.106605351 | -30 | +----------------------------+------------+------------+-------------------+-------------------+ 

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