Yes I just want the largest polygons. The problem being that when I
simplify the polygon it appears to need a lot more simplification due to
these islands rather than if it just did did one mainland polygon (
asGeoJson comes in at 437 polygons rather than 1 polygon). Not sure why
GeoJson can split it into multiple polygons but Dump[] just hands me one.
Was hoping to use ST_Area but currently cannot break down the single
polygon.
Interestingly QGIS can, if I do single to multipart it can break down into
main landmass and islands. What might be an equivalent postgis method for
doing this?
On Mon, 27 Jan 2014 19:15:18 -0000, Morten Sickel <mor...@sickel.net>
wrote:
It depends on what you mean with "remove" - do you want to just have the
large polygons without the area that is covered by the small ones or do
you want to add the area of the small polygons onto one or more of the
larges? (e.g. how one typically wants to handle shiver polygons)
In the first case it is as easy as a query like
select the_geom where ST_area(the_geom) > ...
Morten
Tom McCallum skrev:
Hi all,
If I have a polygon geometry field which seems to be made up of a large
number of tiny polygons and some larger ones, what is the best way to
remove polygons below a certain size? Would I need to preprocess this
and
save in a new table/record or can I dynamically do it?
Thanks
Tom
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