[OSM-dev] Measuring the current state of play wrt new contributor terms

Stephan Knauss osm at stephans-server.de
Wed Aug 11 09:20:39 BST 2010


Hi Jim,

nice idea. The code could also be reused for the revert scripts in case 
some Teleatlas data has to be removed aagain.

Jim Brown wrote:
>     * Where geometries have changed:
>           o If the object has a prior version, take the prior version of
>             the geometry and then apply subsequent geometry edits past
>             theirs
>           o If the object does not have a prior version, then it is
>             probably lost to the db along with its tags.


I'm not sure about this. At least on the node level it should be changed.

If a node is moved then this is a combination of two actions: First 
delete old coordinates second insert new coordinates.

So there is nothing left from the previous coordinate that needs to be 
removed. Even the information that there is an object is implicitly 
inserted again by the new editor.

 From the algorithmic POV:
reset the geometry to 0,0 (or some other magic number). Then apply 
subseqent geometries.
In case at the end the geometry is still 0,0 remove the node (with its tags)


o If the object has a newer geometry use the newest geometry available
o If the object has no newer geometry but a prior version, take the
   prior version
o If the object does not have other geometry information, then it is
   probably lost to the db along with its tags.

Stephan



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