PostGIS 1.5.8 Manual - Fedora Project Packages GIT repositories

PostGIS 1.5.8 Manual102 / 310This function supports 3d and will not drop the z-index.This method supports Circular Strings and CurvesExamplespostgis=# SELECT ST_IsClosed(’LINESTRING(0 0, 1 1)’::geometry);st_isclosed-------------f(1 row)postgis=# SELECT ST_IsClosed(’LINESTRING(0 0, 0 1, 1 1, 0 0)’::geometry);st_isclosed-------------t(1 row)postgis=# SELECT ST_IsClosed(’MULTILINESTRING((0 0, 0 1, 1 1, 0 0),(0 0, 1 1))’::geometry);st_isclosed-------------f(1 row)postgis=# SELECT ST_IsClosed(’POINT(0 0)’::geometry);st_isclosed-------------t(1 row)postgis=# SELECT ST_IsClosed(’MULTIPOINT((0 0), (1 1))’::geometry);st_isclosed-------------t(1 row)See AlsoST_IsRing7.4.12 ST_IsEmptyST_IsEmpty — Returns true if this Geometry is an empty geometry . If true, then this Geometry represents the empty point set -i.e. GEOMETRYCOLLECTION(EMPTY).Synopsisboolean ST_IsEmpty(geometry geomA);DescriptionReturns true if this Geometry is an empty geometry . If true, then this Geometry represents an empty geometry collection,polygon, point etc.