Add support for OSM shapes

danvk / comparea

Compare geographic features

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Add support for OSM shapes #10

Closed danvk closed 9 years ago

danvk commented 9 years ago

OSM is a great source for smaller-scale polygons, e.g. Golden Gate Park and Central Park. It would be great if Comparea could support these shapes, too.

Possible ways to support:

URL hacking, e.g. comparea.org/osm:158602261+osm:161202890
Importing important ones, e.g. ones with cross-referenced Wikipedia articles

It would be great to get city outlines, too, but it's not clear to me if these are simple ways in OSM.

danvk commented 9 years ago

This command will fetch all the lat/lon pairs for an OSM way:

curl 'http://overpass.osm.rambler.ru/cgi/interpreter?data=%5Bout:json%5D;(way(158602261);%3E;);out;'

danvk commented 9 years ago

I implemented this by importing a few select ways and relations from OSM and removing water. The criteria were:

has an English Wikipedia article (note: this eliminates relations like Paris)
is either:
- admin_level > 4, not a county and has a population >= 100,000 according to Freebase.
- leisure=park with Wikipedia articles in >= 10 languages.