114 | | == '''Objective 0.1.6e - Being able to intersect vector and raster to produce vector.''' == |
115 | | |
116 | | List of PostGIS functions similar or related to ST_GetBBox(), ST_Envelope() and ST_Polygon(): |
117 | | |
118 | | [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.) |
119 | | |
120 | | ST_box(geometry) (return a PostgreSQL box object) |
121 | | |
122 | | [http://postgis.refractions.net/documentation/manual-1.4/ST_Box2D.html ST_box2d(geometry)] (return a box2d object) |
123 | | |
124 | | [http://postgis.refractions.net/documentation/manual-1.4/ST_Box3D.html ST_box3d(geometry)] (return a box3d object) |
125 | | |
126 | | getBBOX(geometry) (Deprecation in 1.2.3) |
127 | | |
128 | | [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. |
129 | | |
130 | | envelope(geometry) (Deprecation in 1.2.3) |
131 | | |
132 | | [http://postgis.refractions.net/documentation/manual-1.4/ST_Extent.html ST_extent(geometry set)] |
133 | | |
134 | | [http://postgis.refractions.net/documentation/manual-1.4/ST_ExteriorRing.html ST_ExteriorRing(geometry)] |
135 | | |
136 | | [http://postgis.refractions.net/documentation/manual-1.4/ST_ConvexHull.html ST_ConvexHull(geometry)] |
137 | | |
138 | | '''Function definitions for WKT Raster 0.1.6''' |
139 | | |
140 | | ST_GetBBox(raster) (not yet implemented but planned) is replaced with ST_Envelope() since there is no more an equivalent ST_GetBBox function in PostGIS. |
| 114 | == '''Objective 0.1.6e - Being able to intersect geometries and rasters to produce geometries .''' == |