[postgis-users] Simplify a perfect (hierarchical) partition of polygons (ST_SimplifyPreserveTopology and friends)

[Martin Tomko]

Dear Stephen, Sandro,
Thanks again for the pointers.
I have looked through a few links, and in particular the presentation from
October 2011 (FOSS2011). The page 10 summarizes exactly what I am looking
for, and so does the conceptual model on p17
(http://strk.keybit.net/projects/postgis/Paris2011_TopologyWithPostGIS_2_0.
pdf).
But I need a clarification - two questions:
- is the hierarchicalTopoGeom somehow explicitly created, or is it just a
part of topoGeom internal implementation? Can I profit of this hierarhcial
topological concept directly?
- If I build a TopoGEom, and run ST_SimplifyPReserveTopology on it, will
the nodes be respected and the topology preserved in the output (the
result should be a topogeom...)?

I think that the best way for this hierarchical scenarios is to start from
the finest geographies and aggregate upwards on the generalised ones. I
will have to somehow control for the intermediate nodes that are not valid
for higher order geometries (joins of suburbs on the state boundary,
etcŠ), but that I could solve somehow.


Thanks,
Martin
-- 

Martin Tomko, PhD.
Senior Project Manager, Information Infrastructure Design, AURIN
Level 5, Architecture Building
University of Melbourne VIC 3010
AUSTRALIA

T:  +61 3 9035 3298
E:  tomkom at unimelb.edu.au <mailto:tomkom at unimelb.edu.au>
W: www.aurin.org.au <www.aurin.org.au> W: http://www.tomko.org






On 14/03/12 6:00 AM, "postgis-users-request at postgis.refractions.net"
<postgis-users-request at postgis.refractions.net> wrote:

>Re: [postgis-users] Simplify a perfect (hierarchical)
>	partition of polygons (ST_SimplifyPreserveTopology and friends)