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Hello all, I'm working on a time lapse animation that shows when sidewalk tags were added in the Portland, OR, metro area. I can use overpass to get the streets that have sidewalk tags and use their last edit time stamp, but a lot of them have been modified again since the initial addition of the sidewalk=* tag. I'm wondering if it is possible to query the attic data to learn when a particular key was first added to each street in the area, and by whom. I've spent a good amount of time examining the documentation, but have been unable to find any examples like this. Is it possible? Thank you very much, Madeline |
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There's no direct way in Overpass to examine differences between versions of an object. There also is not a way to directly ask for a specific version of an object (I say direct because with enough date queries it should be possible to retrieve all of the versions you are interested in). You would need to fetch the objects you are interested in and then fetch the history for each one from the OSM API or pull them out of a history dump. There are some existing tools for building history animations: https://github.com/MaZderMind/osm-history-renderer/blob/master/TUTORIAL.md Maybe that would be an alternative place to start. 1
There's already an enhancement request to request a specific version of an object, see: https://github.com/drolbr/Overpass-API/issues/282. Full history processing is not for the faint-hearted, it needs a 51 GB (!) download to start with, unless you find an up to date history extract for your area. MaZderMind used to provide some of these for a few areas, but they don't seem to get updated anymore since at least a year now.
(12 Aug '16, 22:07)
mmd
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