[Talk-ca] [bot] Proposal to fix issue with duplicated inner polygons in Canada

[john whelan]

It has my vote as well.

Cheerio John

On Thu, Dec 2, 2021, 12:07 Daniel @jfd553 <jfd553 at hotmail.com> wrote:

> Bonjour Pauline,
>
> IMHO, this is a good initiative. OSM best practices have evolved with the
> community and keeping data as close as possible to current rules - when
> possible - is in everyone’s interest.
>
> The current problem arises from a 2009 consensus made within the Canadian
> OSM community, which was later documented in the wiki [1] (look at the
> history). At that time, there were no such precise rules on the structure
> of data or on the procedure for importing data.
>
> So, as long as the relevant codes of conduct are respected, I agree with
> the project.
>
>
>
> Daniel
>
>
>
> [1] https://wiki.openstreetmap.org/wiki/CanVec:_Geometric_Model
>
>
>
> *From:* OSM [mailto:OSM at tomtom.com]
> *Sent:* Thursday, December 02, 2021 04:44
> *To:* talk-ca at openstreetmap.org
> *Subject:* [Talk-ca] [bot] Proposal to fix issue with duplicated inner
> polygons in Canada
>
>
>
> Hello everyone,
> Bonjour à tous,
>
> I'm Paulina from TomTom.
>
> We would like to join your conversation and introduce our team to you.
>
> You might have read about TomTom’s OSM activities in this weekly OSM
> overview <https://weeklyosm.eu/archives/14716>, or in our own blog posts (this
> one
> <https://www.tomtom.com/blog/maps/tomtom-openstreetmaps-mapmetrics-map-editing/>
> and this one
> <https://www.tomtom.com/blog/maps/the-battle-for-quality-maps/>). Our
> team is performing data analysis in OSM to identify issues worth fixing.
>
> In Canada in particular, we've encountered an issue related to double
> inner polygons. The geometry of the multipolygon inner ring is duplicated:
> one is in a relation but without a tag and another has tags but is not part
> of the relation (Osmose Rule 1170 Class 1
> <http://osmose.openstreetmap.fr/en/issues/open?item=1170&source=&class=1&username=&bbox=>
> "Double inner polygon").
>
> Following the Automated Edits code of conduct
> <https://wiki.openstreetmap.org/wiki/Automated_Edits_code_of_conduct>, we
> have developed a bot that would be useful in solving this issue. All
> details about it (explanation of the algorithm, examples, etc.) are
> described on the dedicated wiki page
> https://wiki.openstreetmap.org/wiki/Automated_edits/TTmechanicalupdates/Fix_issue_with_duplicated_inner_polygons_in_Canada
> .
>
> Our internal analysis has shown that this problem is primarily caused by
> an import of CanVec data. According to the CanVec OSM wiki documentation
> <https://wiki.openstreetmap.org/wiki/CanVec#Issues_found_in_OSM>, the
> issue is already known by the community and mentioned there as "Duplicate
> land features". The bot is suitable for CanVec, but the double inner
> polygon issue appears in around 3,000 examples that do not have a source
> mentioned in their tags. For these issues, we would like your opinion about
> whether we should also fix them (please see the Discussion
> <https://wiki.openstreetmap.org/wiki/Automated_edits/TTmechanicalupdates/Fix_issue_with_duplicated_inner_polygons_in_Canada#Discussion> part
> in the wiki documentation).
>
> It is worth mentioning that in the past, we've already gained experience
> with mechanical updates in OSM by running a bot to update night-time urban
> speed limits in Poland (see the proposal mentioned in this weeklyOSM
> summary <https://weeklyosm.eu/archives/14709>, and the forum thread
> <https://forum.openstreetmap.org/viewtopic.php?id=73116> about this
> action).
>
> We propose to do a test run by updating invalid polygons in Southwestern
> Ontario, where 800 cases are logged by the Osmose rule.
>
> Per the Automated Code of Conduct, we will wait for your feedback before
> we begin. We look forward to building and improving OSM together with you!
>
> Kind regards,
> Paulina.
>
>
> _______________________________________________
> Talk-ca mailing list
> Talk-ca at openstreetmap.org
> https://lists.openstreetmap.org/listinfo/talk-ca
>
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