ST_MaxX, ST_MaxY, ST_MaxZ, ST_MaxM

Determine the maximum x, y, z, or m (measure) coordinate of a geometry or geometry collection.

There is a separate function for each coordinate:
  • ST_MaxX
  • ST_MaxY
  • ST_MaxZ
  • ST_MaxM

Syntax

ST_MaxX(geo);
ST_MaxY(geo);
ST_MaxZ(geo);
ST_MaxM(geo);
geo
The input geometry.

Type: VARCHAR(ANY)

Returns

A value of type DOUBLE that is the maximum coordinate of all the elements of the input geometry, or NULL if input geometry is empty.

Examples

SELECT inza..ST_MaxM(inza..ST_WKTToSQL('POLYGON ((10 10 0 50, 10 20 1 60, 20 20 2 70, 20 15 3 80, 10 10 0 50))'));
 
ST_MAXM
-------
80
(1 row)
SELECT inza..ST_MaxX(inza..ST_WKTToSQL('POLYGON ((10 10, 10 20, 20 20, 20 15, 10 10))'));
 
ST_MAXX
---------
20
(1 row)
SELECT inza..ST_MaxX(inza..ST_WKTToSQL('GeometryCollection(POINT (10 10),POINT (30 30), LINESTRING (15 15, 20 20))'));
 
ST_MAXX
---------
30
(1 row)
SELECT inza..ST_MaxY(inza..ST_WKTToSQL('POLYGON ((10 10, 10 30, 20 20, 20 15, 10 10))'));
 
ST_MAXY
---------
30
(1 row)
SELECT inza..ST_MaxY(inza..ST_WKTToSQL('GeometryCollection(POINT (10 10),POINT (30 15), LINESTRING (15 15, 20 20))'));
 
ST_MAXY
---------
20
(1 row)
SELECT inza..ST_MaxZ(inza..ST_WKTToSQL('POLYGON ((10 10 0, 10 20 1, 20 20 2, 20 15 3,
            10 10 0))'));
 
ST_MAXZ
---------
3
(1 row)
SELECT inza..ST_MaxZ(inza..ST_WKTToSQL('POLYGON ((10 10 10 10, 10 20 20 20, 20 20 20
            20, 20 15 15 40, 10 10 10 10))'));
 
ST_MAXZ
---------
20
(1 row)
SELECT inza..ST_MaxZ(inza..ST_WKTToSQL('LINESTRING EMPTY')); 

ST_MAXZ
---------
(1 row)