PostGIS 1.5.8 Manual - Fedora Project Packages GIT repositories

PostGIS 1.5.8 Manual285 / 3108.9.2 PostGIS Functions new, behavior changed, or enhanced in 1.4The functions given below are PostGIS functions that were introduced or enhanced in the 1.4 release.• Populate_Geometry_Columns - Ensures geometry columns have appropriate spatial constraints and exist in the geometry_columnstable. Availability: 1.4.0• ST_AsSVG - Returns a Geometry in SVG path data given a geometry or geography object. Availability: 1.2.2 . Availability:1.4.0 Changed in PostGIS 1.4.0 to include L command in absolute path to conform to http://www.w3.org/TR/SVG/paths.html#PathData• ST_Collect - Return a specified ST_Geometry value from a collection of other geometries. Availability: 1.4.0 - ST_Collect(geomarray)was introduced. ST_Collect was enhanced to handle more geometries faster.• ST_ContainsProperly - Returns true if B intersects the interior of A but not the boundary (or exterior). A does not containproperly itself, but does contain itself. Availability: 1.4.0 - requires GEOS >= 3.1.0.• ST_Extent - an aggregate function that returns the bounding box that bounds rows of geometries. Availability: 1.4.0 As of1.4.0 now returns a box3d_extent instead of box2d object.• ST_GeoHash - Return a GeoHash representation (geohash.org) of the geometry. Availability: 1.4.0• ST_IsValidReason - Returns text stating if a geometry is valid or not and if not valid, a reason why. Availability: 1.4 - requiresGEOS >= 3.1.0.• ST_LineCrossingDirection - Given 2 linestrings, returns a number between -3 and 3 denoting what kind of crossing behavior.0 is no crossing. Availability: 1.4• ST_LocateBetweenElevations - Return a derived geometry (collection) value with elements that intersect the specified rangeof elevations inclusively. Only 3D, 4D LINESTRINGS and MULTILINESTRINGS are supported. Availability: 1.4.0• ST_MakeLine - Creates a Linestring from point geometries. Availability: 1.4.0 - ST_MakeLine(geomarray) was introduced.ST_MakeLine aggregate functions was enhanced to handle more points faster.• ST_MinimumBoundingCircle - Returns the smallest circle polygon that can fully contain a geometry. Default uses 48 segmentsper quarter circle. Availability: 1.4.0 - requires GEOS• ST_Union - Returns a geometry that represents the point set union of the Geometries. Availability: 1.4.0 - ST_Union wasenhanced. ST_Union(geomarray) was introduced and also faster aggregate collection in PostgreSQL. If you are using GEOS3.1.0+ ST_Union will use the faster Cascaded Union algorithm described in http://blog.cleverelephant.ca/2009/01/must-fasterunions-in-postgis-14.html8.9.3 PostGIS Functions new in 1.3The functions given below are PostGIS functions that were introduced in the 1.3 release.• ST_AsGeoJSON - Return the geometry as a GeoJSON element. Availability: 1.3.4• ST_SimplifyPreserveTopology - Returns a "simplified" version of the given geometry using the Douglas-Peucker algorithm.Will avoid creating derived geometries (polygons in particular) that are invalid. Availability: 1.3.3