ST_IsPolygonCW - Amazon Redshift
SyntaxArgumentsReturn typeExamples

Amazon Redshift will no longer support the creation of new Python UDFs starting Patch 198. Existing Python UDFs will continue to function until June 30, 2026. For more information, see the blog post .

ST_IsPolygonCW

ST_IsPolygonCW returns true if the 2D projection of the input polygon or multipolygon is clockwise. If the input geometry is a point, linestring, multipoint, or multilinestring, then true is returned. For geometry collections, ST_IsPolygonCW returns true if all the geometries in the collection are clockwise.

Syntax

ST_IsPolygonCW(geom)

Arguments

geom

A value of data type GEOMETRY or an expression that evaluates to a GEOMETRY type.

Return type

BOOLEAN

If geom is null, then null is returned.

Examples

The following SQL checks if the polygon is clockwise. 

SELECT ST_IsPolygonCW(ST_GeomFromText('POLYGON((7 9,8 7,11 6,15 8,16 6,17 7,17 10,18 12,17 14,15 15,11 15,10 13,9 12,7 9),(9 9,10 10,11 11,11 10,10 8,9 9),(12 14,15 14,13 11,12 14))'));

 st_ispolygonccw
----------
 true