[postgis-devel] wktraster ST_ConvexHull
jorgearevalo at gis4free.org
Wed Apr 7 08:57:37 PDT 2010
On Wed, Apr 7, 2010 at 5:51 PM, Pierre Racine
<Pierre.Racine at sbf.ulaval.ca> wrote:
>>> One problem I see is that people see the result of ST_Dump as simple polygons when the result of
>>ST_AsPolygon is not necessarily simple polygons. You get simple polygons only when you add the
>>'CONTIGUOUS' keyword to the function (ST_AsPolygon(raster, integer, 'CONTIGUOUS')).
>>Then, the 'CONTIGUOUS' keyword is used only when you want single
>>polygons in the output geometry (I suppose this terminology, with
>>CONTIGUOUS word, comes from any GIS field...). I think this could be a
>>problem, because GDALPolygonize allways generates standard WKB
>>polygons. I've used this function for st_aswktpolygon. So, the
>>function always works as if 'CONTIGUOUS' option is specified. Should
>>we codify our own polygonize function? We had this discussion some
> If GDAL is producing only contiguous polygon then our (new) ST_Dump function should do the same and forget about the 'CONTIGUOUS' variant.
Ok. Much easier.
>>>>Getting to names -- ST_AsWKTPolygon should not start with an ST_ if it is
>>>>not intended for end user use.
>>> Jorge, could we rename ST_AsWKTPolygon to RasterAsWKTPolygon?
>>Of course. We should avoid "ST" in functions not intended for end-user
>>use. But, do we all agree on that name? Seems Regina prefer a name
>>like "ExtractAsWKTPolygons". I personally like this name. Or
> Probably more something like DumpAsWKTPolygon(s)() (and ST_DumpAsPolygon(s)()). We still have to settle the "s" issue.
Yes, I'm following the thread. I support ending "s"
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