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Finding multipolygons with more than one ‘outer’ way. Overpass?

I'd like to find multipolygons that have more than one member with the role 'outer'.

Is there a way to do that with the Overpass API, or would I have to wait for https://github.com/drolbr/Overpass-API/issues/197 to get written?

Would there be any other way to do this?

overpass relations multipolygon

asked 10 Dec '16, 01:16

Stereo
356●2●5●13
accept rate: 11%

2 Answers:

If you are willing to put up with a beta quality program I am working on, you can use osmium-filter. It can do a query like that: osmium-filter-simple INPUTFILE -e '@relation and (@members[@role=="outer"] > 1)' -o OUTPUTFILE. It doesn't support giving you all the ways and nodes needed for these relations yet, if you need that, you can use the Osmium tool (to be more exact, osmium getid). Other options include writing your own program using libosmium, PyOsmium, or node-osmium (see http://osmcode.org/).

answered 10 Dec '16, 09:30

Jochen Topf
5.2k●5●50●74
accept rate: 31%

edited 10 Dec '16, 09:34

Thank you Jochen, I'll give that a go!

Would you also happen to have a way of finding old-style multipolygons with it?

(10 Dec '16, 12:56) Stereo

Have a look at https://github.com/osmcode/osm-area-tools . There are tools that can find old-style multipolygons. I use that to create the overlay on http://area.jochentopf.com/map/index.html for instance. But you can also just download the old-style mps from http://area.jochentopf.com/ updated daily.

(10 Dec '16, 14:36) Jochen Topf

Wow, osmium-filter is impressively fast! It's an exciting tool, and I hope that you'll find time to document it :).

'@relation and "type"="multipolygon" and (@members[@role=="outer"] > 1)' did the trick.

(10 Dec '16, 14:38) Stereo

I ended up doing it in overpass:

[out:xml][timeout:25];
{{geocodeArea:Luxembourg}}->.searchArea;
// gather results
(
  relation["type"="multipolygon"](if: count_by_role("outer") > 1 )(area.searchArea);
  relation["type"="multipolygon"](if: count_members() == 1 )(area.searchArea);

);
// print results
out meta;
>;
out meta qt;

answered 09 May '21, 21:44

Stereo
356●2●5●13
accept rate: 11%