Permanent ID: Unterschied zwischen den Versionen

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(Weiterleitung nach Permanent ID for OSM erstellt)
 
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This is an '''unofficial proposal for a "permanent ID" (osm_pid) for OpenStreetMap ([[OSM]])'''.
#REDIRECT [[Permanent_ID_for_OSM]]
 
See https://wiki.openstreetmap.org/wiki/Permanent_ID for a more official state of discussions.
 
The goal is to get an opaque fixed length ASCII string. And that are the design considerations:
 
* The OSM id alone is not stable enough (as probably most agree); and it can represent many concepts (and that's by design in OSM).
* The version no. of the object is needed which makes clear which tags are (or have been) referred to.
* Coordinates are needed, because a change of the way and area geometries does not increment the version number.
 
So a stable Permanent ID could have the following form (which leads to a fixed length string of 35 chars in total):
 
  [N|W|R]<osm_id>#<version>[+|-]<lon>[+|-]<lat>
 
where:
* N,W,R stands for Node, Way, or Relation.
* osm_id ann unsigned big integer ("digits").
* version is an unsigned integer with a hash in front.
* coordinates (lat/lon) are signed floats (always showing the +/- sign), with a maximum of 6 digits. In case of a line (linestring) or an area/relation (polygon) geometries the coordinates taken into account are the lat/lon minimum of the geometry.
 
Example: "Schloss Kyburg" (Castle Kyburg) has relation 1169711, version #5 at coordinates 47.4584, 8.74343 which becomes following Permanent ID:
 
  osm_pid = R1169711#5+47.4584+8.74343
 
Service: In order to be really useful, a service should be implemented, which returns most recent Permanent ID even if an object has been changed (thus having another Permanent ID).
 
NOTE: Encoding OSM id with type (Node, Way, Relation) as integer (64 bit): osm_id = <node id> × 10 (eg. 123 → 1230), osm_id =  (<way id> × 10) + 1 (eg. 123 → 1231), osm_id (<relation id> × 10) + 4 (eg. 123 → 1234). (Source: Mapbox, see [https://docs.mapbox.com/vector-tiles/reference/mapbox-streets-v8/#openstreetmap-ids]). Example: "Schloss Kyburg" is a relation with id 1169711, so it becomes 11697114.

Aktuelle Version vom 19. Juni 2019, 20:04 Uhr

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