Changes between Version 55 and Version 56 of WKTRaster/SpecificationWorking01
- Timestamp:
- 12/16/09 10:19:40 (15 years ago)
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TabularUnified WKTRaster/SpecificationWorking01
v55 v56 166 166 == '''Objective 0.1.6e - Being able to intersect vector and raster to produce vector.''' == 167 167 168 List of PostGIS functions similar or related to ST_GetBBox(), ST_Envelope() ,ST_Shape():169 170 ST_Boundary(geometry)(not really - always return a geometry a dimension lower - i.e. the boundary of a polygon is a polyline.)168 List of PostGIS functions similar or related to ST_GetBBox(), ST_Envelope() and ST_Shape(): 169 170 [http://postgis.refractions.net/documentation/manual-1.4/ST_Boundary.html ST_Boundary(geometry)] (not really - always return a geometry a dimension lower - i.e. the boundary of a polygon is a polyline.) 171 171 172 172 ST_box(geometry) (return a PostgreSQL box object) 173 173 174 ST_box2d(geometry)(return a box2d object)175 176 ST_box3d(geometry)(return a box3d object)174 [http://postgis.refractions.net/documentation/manual-1.4/ST_Box2D.html ST_box2d(geometry)] (return a box2d object) 175 176 [http://postgis.refractions.net/documentation/manual-1.4/ST_Box3D.html ST_box3d(geometry)] (return a box3d object) 177 177 178 178 getBBOX(geometry) (Deprecation in 1.2.3) 179 179 180 ST_Envelope(geometry)Returns the minimum bounding box for the supplied geometry, as a geometry. The polygon is defined by the corner points of the bounding box ((MINX, MINY), (MINX, MAXY), (MAXX, MAXY), (MAXX, MINY), (MINX, MINY)). (PostGIS will add a ZMIN/ZMAX coordinate as well). In PostGIS, the bounding box of a geometry is represented internally using float4s instead of float8s that are used to store geometries. The bounding box coordinates are floored, guarenteeing that the geometry is contained entirely within its bounds. This has the advantage that a geometry's bounding box is half the size as the minimum bounding rectangle, which means significantly faster indexes and general performance. But it also means that the bounding box is NOT the same as the minimum bounding rectangle that bounds the geometry.180 [http://postgis.refractions.net/documentation/manual-1.4/ST_Envelope.html ST_Envelope(geometry)] Returns the minimum bounding box for the supplied geometry, as a geometry. The polygon is defined by the corner points of the bounding box ((MINX, MINY), (MINX, MAXY), (MAXX, MAXY), (MAXX, MINY), (MINX, MINY)). (PostGIS will add a ZMIN/ZMAX coordinate as well). In PostGIS, the bounding box of a geometry is represented internally using float4s instead of float8s that are used to store geometries. The bounding box coordinates are floored, guarenteeing that the geometry is contained entirely within its bounds. This has the advantage that a geometry's bounding box is half the size as the minimum bounding rectangle, which means significantly faster indexes and general performance. But it also means that the bounding box is NOT the same as the minimum bounding rectangle that bounds the geometry. 181 181 182 182 envelope(geometry) (Deprecation in 1.2.3) 183 183 184 ST_extent(geometry set) 185 186 ST_ExteriorRing(geometry) 187 188 ST_ConvexHull(geometry) 184 [http://postgis.refractions.net/documentation/manual-1.4/ST_Extent.html ST_extent(geometry set)] 185 186 [http://postgis.refractions.net/documentation/manual-1.4/ST_ExteriorRing.html ST_ExteriorRing(geometry)] 187 188 [http://postgis.refractions.net/documentation/manual-1.4/ST_ConvexHull.html ST_ConvexHull(geometry)] 189 189 190 190 '''ST_GetBBox(raster) -> polygon geometry''' - Replaced with ST_Envelope() since there is no equivalent function in PostGIS.