Descripción

Devuelve TRUE si los puntos de inicio y final de una LINESTRINGson coincidentes. Para superficies poliédricas , te dice si las superficies son áreas (abiertas) o si son volumétricas (cerradas).

This method implements the OGC Simple Features Implementation Specification for SQL 1.1.

This method implements the SQL/MM specification. SQL-MM 3: 7.1.5, 9.3.3

This function supports 3d and will not drop the z-index.

This method supports Circular Strings and Curves.

Mejora: 2.0.0 se introdujo soporte de superficies poliédricas.

This function supports Polyhedral surfaces.

Ejemplos con lineas y puntos

SELECT ST_IsClosed('LINESTRING(0 0, 1 1)'::geometry);

f

SELECT ST_IsClosed('LINESTRING(0 0, 0 1, 1 1, 0 0)'::geometry);

t

SELECT ST_IsClosed('MULTILINESTRING((0 0, 0 1, 1 1, 0 0),(0 0, 1 1))'::geometry);

f

SELECT ST_IsClosed('POINT(0 0)'::geometry);

t

SELECT ST_IsClosed('MULTIPOINT((0 0), (1 1))'::geometry);

t

Ejemplos con superficies Poliédricas

This example uses a cube.

SELECT ST_IsClosed(ST_GeomFromEWKT('POLYHEDRALSURFACE( ((0 0 0, 0 0 1, 0 1 1, 0 1 0, 0 0 0)),
                ((0 0 0, 0 1 0, 1 1 0, 1 0 0, 0 0 0)), ((0 0 0, 1 0 0, 1 0 1, 0 0 1, 0 0 0)),
                ((1 1 0, 1 1 1, 1 0 1, 1 0 0, 1 1 0)),
                ((0 1 0, 0 1 1, 1 1 1, 1 1 0, 0 1 0)), ((0 0 1, 1 0 1, 1 1 1, 0 1 1, 0 0 1)) )'));

t

This example uses the same cube with one side missing.

SELECT ST_IsClosed(ST_GeomFromEWKT('POLYHEDRALSURFACE( ((0 0 0, 0 0 1, 0 1 1, 0 1 0, 0 0 0)),
                ((0 0 0, 0 1 0, 1 1 0, 1 0 0, 0 0 0)), ((0 0 0, 1 0 0, 1 0 1, 0 0 1, 0 0 0)),
                ((1 1 0, 1 1 1, 1 0 1, 1 0 0, 1 1 0)),
                ((0 1 0, 0 1 1, 1 1 1, 1 1 0, 0 1 0)) )'));

f

Ver también

ST_IsRing