[OSM-dev] Get geometries out of OSM changes file

[Yves]

I produce a daily and weekly visualisation of change on Opensnowmap, but a ski piste extract being small, I reload the archive extract in a DB to get the geometry.
I haven't find a more clever solution : if you want to know what was, you have to have it one way or another and I don't know any service offering that easily.
Maybe Ohsome?
Yves 

Le 21 mars 2021 19:15:08 GMT+01:00, "François Lacombe" <fl.infosreseaux at gmail.com> a écrit :
>Thank you Darafei
>
>You link points me to an OverpassAPI endpoint and I don't get how I'm able
>to produce augmented diff from an osc file.
>Osmchange is mentioned as a reader of augmented diff, but not as a producer.
>
>Any extra elaboration will be welcome, all the best
>
>François
>
>Le dim. 21 mars 2021 à 18:17, Darafei "Komяpa" Praliaskouski <me at komzpa.net>
>a écrit :
>
>> https://wiki.openstreetmap.org/wiki/Overpass_API/Augmented_Diffs
>>
>> нд, 21 сак 2021, 20:01 карыстальнік François Lacombe <
>> fl.infosreseaux at gmail.com> напісаў:
>>
>>> Hi all
>>>
>>> For the needs of ProjetDuMois statistics computing chain, I'm looking for
>>> an appropriate logic to get geometries associated with osm changes in an
>>> osc file, particularly for past versions.
>>>
>>> According to this discussion, it sounds to not be easy.
>>>
>>> https://help.openstreetmap.org/questions/58931/osc-to-osm-change-file-to-osm-osmium/58948
>>>
>>> Currently, we convert an OSC file to CSV without any geometry information
>>>
>>> https://github.com/vdct/ProjetDuMois/blob/master/db/10_project_update.js#L275
>>> with following xslt sheet
>>> https://github.com/vdct/ProjetDuMois/blob/master/db/osc2csv.xslt
>>>
>>> We now aim to group and count changes against some administrative
>>> boundaries. As a given feature can change of admin area between two
>>> versions, we must filter the changes we're interested in, intersect each of
>>> them with selected admin boundaries and finally count how may they are in
>>> each admin boundary.
>>>
>>> Despite I'll be able to get lat/lon for nodes, rebuild linestrings for
>>> ways will be tricky as we'll have to not only check against nodes ids but
>>> timestamps as well.
>>>
>>> It's not a problem to do that each day with daily updates but issues
>>> occurs when we drop the database and try to get back 2 or 3 month with no
>>> geometry history at all.
>>> See this chart (in French) :
>>> https://github.com/vdct/ProjetDuMois/issues/188#issuecomment-802221915
>>>
>>> I'll be happy to discuss about such process here as I think someone may
>>> already had to solve it.
>>> Thanks in advance, all the best
>>>
>>> François
>>> _______________________________________________
>>> dev mailing list
>>> dev at openstreetmap.org
>>> https://lists.openstreetmap.org/listinfo/dev
>>>
>>
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