PostGIS 1.5.8 Manual - Fedora Project Packages GIT repositories

PostGIS 1.5.8 Manual253 / 310BOX(2312882 110666,2312990 110724)--10 meter expanded 3d box of a 3d boxSELECT ST_Expand(CAST(’BOX3D(778783 2951741 1,794875 2970042.61545891 10)’ As box3d),10)st_expand-----------------------------------------------------BOX3D(778773 2951731 -9,794885 2970052.61545891 20)--10 meter geometry astext rep of a expand box around a point geometrySELECT ST_AsEWKT(ST_Expand(ST_GeomFromEWKT(’SRID=2163;POINT(2312980 110676)’),10));st_asewkt------------------------------------------------------------------------------------------------- ←↪SRID=2163;POLYGON((2312970 110666,2312970 110686,2312990 110686,2312990 110666,2312970110666))←↪See AlsoST_AsEWKT, ST_Buffer, ST_DWithin, ST_GeomFromEWKT,ST_GeomFromText, ST_SRID7.12.6 ST_ExtentST_Extent — an aggregate function that returns the bounding box that bounds rows of geometries.Synopsisbox3d_extent ST_Extent(geometry set geomfield);DescriptionST_Extent returns a bounding box that encloses a set of geometries. The ST_Extent function is an "aggregate" function in theterminology of SQL. That means that it operates on lists of data, in the same way the SUM() and AVG() functions do.Since it returns a bounding box, the spatial Units are in the units of the spatial reference system in use denoted by the SRIDST_Extent is similar in concept to Oracle Spatial/Locator’s SDO_AGGR_MBRNoteSince ST_Extent returns a bounding box, the SRID meta-data is lost. Use ST_SetSRID to force it back into a geometrywith SRID meta data. The coordinates are in the units of the spatial ref of the orginal geometries.NoteST_Extent will return boxes with only an x and y component even with (x,y,z) coordinate geometries. To maintain x,y,zuse ST_Extent3D instead.NoteAvailability: 1.4.0 As of 1.4.0 now returns a box3d_extent instead of box2d object.