<html><head></head><body><div class="ydp8c9e6047yahoo-style-wrap" style="font-family:verdana, helvetica, sans-serif;font-size:13px;"><div id="ydp8c9e6047yiv2333872735"><div><div class="ydp8c9e6047yiv2333872735ydpcb5f57acyahoo-style-wrap" style="font-family:verdana, helvetica, sans-serif;font-size:13px;"><div><div dir="ltr"> <div dir="ltr" data-setdir="false"><div dir="ltr" data-setdir="false">Petit rappel pour ceux moins familiers avec les imports Canvec. Il est bon de bien connaître la structure des données et doublons éventuels à corriger. Aussi JOSM est très utile pour repérer les chemins en doublon et corriger.</div><div><br></div><div dir="ltr" data-setdir="false">Les développeurs OSM mentionnent régulièrement des multipolygones bois (imports Canvec) très grands et complexes qui causent des problèmes de traitement de données dans la base de données OSM. Il faut donc éviter de jumeler les multipolygones bois, et plutôt simplifier lorsque possible.<br></div><br clear="none"><div>Aussi, on rencontre souvent des chemins en doublon pour décrire et le lac et les zones à exclure d'un multipolygone. Tobermory Lake (60852636) est un exemple intéressant à ce sujet. Avec JOSM, on clique sur les bords du lac pour voir si des doublons existent.</div><div><br></div><div>Ici</div>- le lac https://www.openstreetmap.org/way/60852636<br clear="none">- la zone à exclure du multipolygone (role=inner) https://www.openstreetmap.org/way/60854569<br clear="none">- le multipolygone https://www.openstreetmap.org/way/946291<br clear="none"><br clear="none">De plus, on retrouve un polygone couvrant une partie du lac pour le marécage adjacent au lac (natural=wetland).<br clear="none">https://www.openstreetmap.org/way/60852071<br clear="none"><br clear="none"></div><br></div><div dir="ltr" data-setdir="false">Ici on peut par exemple ne conserver que le lac (<span>way/60852636) et effacer le doublon pour le role inner (<span>way/60854569</span>) et réviser la relation multipolygone pour y indiquer <span><span>way/60852636</span></span> avec role=inner.<br></span></div><div dir="ltr"><br clear="none"></div><div class="ydp8c9e6047yiv2333872735ydpcb5f57acsignature"><span style="font-style:italic;color:rgb(0, 0, 191);font-weight:bold;"> <br clear="none"><font style="background-color:inherit;" face="garamond, new york, times, serif">Pierre </font><br clear="none"></span></div></div>
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Le mardi 7 juillet 2020 11 h 34 min 08 s UTC−4, James <james2432@gmail.com> a écrit :
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<div><div class="ydp8c9e6047yiv2333872735ydpe2927590yqt7098422131" id="ydp8c9e6047yiv2333872735ydpe2927590yqt85190">_______________________________________________<br clear="none">Talk-ca mailing list<br clear="none"><a shape="rect" href="mailto:Talk-ca@openstreetmap.org" rel="nofollow" target="_blank">Talk-ca@openstreetmap.org</a><br clear="none"><a shape="rect" href="https://lists.openstreetmap.org/listinfo/talk-ca" rel="nofollow" target="_blank">https://lists.openstreetmap.org/listinfo/talk-ca</a><br clear="none"></div></div>
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</div></div></div></div><div class="ydp5673c498yiv2333872735yqt6664028756" id="ydp5673c498yiv2333872735yqt07023"><div id="ydp5673c498yiv2333872735ydpe2927590yiv2047391759"><div><div>I don't think canvec is updating these things on a regular basis, OSM after corrections are usually more accurate than canvec anyways and doubt would update data from Canvec to fix outdated data</div><br clear="none"><div class="ydp5673c498yiv2333872735ydpe2927590yiv2047391759yqt7098422131" id="ydp5673c498yiv2333872735ydpe2927590yiv2047391759yqt70572"><div class="ydp5673c498yiv2333872735ydpe2927590yiv2047391759gmail_quote"><div class="ydp5673c498yiv2333872735ydpe2927590yiv2047391759gmail_attr" dir="ltr">On Tue., Jul. 7, 2020, 11:27 a.m. Hannes Röst, <<a shape="rect" href="mailto:hannesroest@gmx.ch" rel="nofollow" target="_blank">hannesroest@gmx.ch</a>> wrote:<br clear="none"></div><blockquote class="ydp5673c498yiv2333872735ydpe2927590yiv2047391759gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">Dear Adam and Daniel<br clear="none">
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Thanks a lot, so this answers the question that these are import artefacts and not intended. One question still remains, namely whether we should clean them up and how (joining ways makes sense from the OSM data model but may make a future update based on CANVEC files much harder while adding all ways into a relation would preserve the import but the resulting shape will look funny). My instinct is still to fix the ways unless there is a strong reason against this. One reason I ran into this was trying to match OSM to Wikidata items and of course having 3 ways all called the same name makes this difficult. Let me know what you think<br clear="none">
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Another issue I found was with nodes such as these: 1279897592, 1279898654 and 1279896951 which also seem to come from an import (see [1] for overpass query). I am not sure whether these are duplicate imports or whether they are supposed to indicate the extent of a feature (most east and most western point) of the channel. The wiki indicates to either map this as "natural=strait" and use either a single node, a line or a multipolygon [2] but not as multiple nodes with the same name. Honestly, in this case its a bit hard to see where the supposed "channel" should be, but connecting the nodes to a line would seem sensible here to me, any thoughts?<br clear="none">
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Best<br clear="none">
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Hannes<br clear="none">
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[1] <a shape="rect" href="http://overpass-turbo.eu/map.html?Q=%5Bout%3Ajson%5D%5Btimeout%3A25%5D%3B%0A(%0A%20%20node%5Bname%3D%22Devil%20Island%20Channel%22%5D%3B%0A)%3B%0Aout%20body%3B%0A%3E%3B%0Aout%20skel%20qt%3B" rel="nofollow" target="_blank">http://overpass-turbo.eu/map.html?Q=%5Bout%3Ajson%5D%5Btimeout%3A25%5D%3B%0A(%0A%20%20node%5Bname%3D%22Devil%20Island%20Channel%22%5D%3B%0A)%3B%0Aout%20body%3B%0A%3E%3B%0Aout%20skel%20qt%3B</a><br clear="none">
[2] <a shape="rect" href="https://wiki.openstreetmap.org/wiki/Tag:natural%3Dstrait#How_to_map" rel="nofollow" target="_blank">https://wiki.openstreetmap.org/wiki/Tag:natural%3Dstrait#How_to_map</a><br clear="none">
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Gesendet: Dienstag, 07. Juli 2020 um 09:56 Uhr<br clear="none">
Von: "Adam Martin" <<a shape="rect" href="mailto:s.adam.martin@gmail.com" rel="nofollow" target="_blank">s.adam.martin@gmail.com</a>><br clear="none">
An: "Hannes Röst" <<a shape="rect" href="mailto:hannesroest@gmx.ch" rel="nofollow" target="_blank">hannesroest@gmx.ch</a>><br clear="none">
Cc: "Talk-CA OpenStreetMap" <<a shape="rect" href="mailto:talk-ca@openstreetmap.org" rel="nofollow" target="_blank">talk-ca@openstreetmap.org</a>><br clear="none">
Betreff: Re: [Talk-ca] NRCan lakes<br clear="none">
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As mentioned by Daniel, this is due to the nature of the CANVEC data import. CANVEC shapefile data is based on tiles and these will chop practically anything into pieces - lakes are just ones of the more noticeable. I have corrected some of these myself as I've come across them. Just be careful in cases where the lake pieces are part of different relations in the area - you will need to adjust those to make sure nothing breaks.<br clear="none">
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Adam <br clear="none">
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On Tue, Jul 7, 2020 at 2:33 AM Hannes Röst <<a shape="rect" href="mailto:hannesroest@gmx.ch" rel="nofollow" target="_blank">hannesroest@gmx.ch</a>[mailto:<a shape="rect" href="mailto:hannesroest@gmx.ch" rel="nofollow" target="_blank">hannesroest@gmx.ch</a>]> wrote:Hello<br clear="none">
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I am a contributor from Toronto and I have a question regarding how to<br clear="none">
treat some of the CanVec 6.0 - NRCan imports, specifically for lakes.<br clear="none">
I came across this lake here:<br clear="none">
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<a shape="rect" href="https://www.openstreetmap.org/way/69275451%5Bhttps://www.openstreetmap.org/way/69275451%5D" rel="nofollow" target="_blank">https://www.openstreetmap.org/way/69275451[https://www.openstreetmap.org/way/69275451]</a><br clear="none">
<a shape="rect" href="https://www.openstreetmap.org/way/69277932" rel="nofollow" target="_blank">https://www.openstreetmap.org/way/69277932</a><br clear="none">
<a shape="rect" href="https://www.openstreetmap.org/way/69745752" rel="nofollow" target="_blank">https://www.openstreetmap.org/way/69745752</a><br clear="none">
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Which is strangely split up into 3 parts and I wonder how to proceed:<br clear="none">
should we fix this and create a single way out of these 3 parts or is<br clear="none">
it beneficial (for comparison to future NRCan database entries) to<br clear="none">
keep them that way and create a relation out of the three? Also, does<br clear="none">
somebody know why the NRCan dataset does this, is this an import<br clear="none">
artefact (splitting into tiles?) and should be corrected when encountered<br clear="none">
or is it part of the original dataset?<br clear="none">
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Best<br clear="none">
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Hannes Rost<br clear="none">
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