Changes between Version 55 and Version 56 of WKTRaster/SpecificationWorking01


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Timestamp:
Dec 16, 2009, 10:19:40 AM (14 years ago)
Author:
pracine
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  • WKTRaster/SpecificationWorking01

    v55 v56  
    166166== '''Objective 0.1.6e - Being able to intersect vector and raster to produce vector.''' ==
    167167
    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.)
     168List 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.)
    171171
    172172ST_box(geometry) (return a PostgreSQL box object)
    173173
    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)
    177177
    178178getBBOX(geometry) (Deprecation in 1.2.3)
    179179
    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.
    181181
    182182envelope(geometry) (Deprecation in 1.2.3)
    183183
    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)]
    189189
    190190'''ST_GetBBox(raster) -> polygon geometry''' - Replaced with ST_Envelope() since there is no equivalent function in PostGIS.