Re: [Tagging] area=yes on polygones (was Block names)
On Wed, May 2, 2012 at 4:53 AM, Pieren pier...@gmail.com wrote: On Tue, May 1, 2012 at 5:56 PM, Anthony o...@inbox.org wrote: What about closed ways tagged with barrier=* and some other ambiguous *=* (e.g. barrier=hedge amenity=marketplace). No, the tag barrier=* is not ambiguous and is self explanatory (does not need to check any tag combination). So you can't map a hedge or a city wall or a ditch as an area? Why not? What if we want to change this in the future? ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] area=yes on polygones (was Block names)
On Tue, May 1, 2012 at 5:56 PM, Anthony o...@inbox.org wrote: What about closed ways tagged with barrier=* and some other ambiguous *=* (e.g. barrier=hedge amenity=marketplace). No, the tag barrier=* is not ambiguous and is self explanatory (does not need to check any tag combination). Btw, by digging a bit more the wiki, I discover that public_transport=station also requires the tag area=yes ([1]) ,,,if the station outline is not a building''' ... although it is clearly specified that the feature is always a closed way (not a possible linear feature). Wow, where is the logic here ? That's another example of area=yes dissemination, used to fix rendering issues and not for disambiguation. Pieren [1] http://wiki.openstreetmap.org/wiki/Tag:public_transport%3Dstation ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] area=yes on polygones (was Block names)
On 4/27/2012 3:25 PM, Nathan Edgars II wrote: While this is ongoing, Pieren continues to remove area=yes from railway=platform, which has been on the page since it was created in 2008: http://wiki.openstreetmap.org/w/index.php?title=Tag:railway%3Dplatformaction=history And Pieren continues to add his opinion to the page. ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] area=yes on polygones (was Block names)
On Tue, May 1, 2012 at 10:36 AM, Nathan Edgars II nerou...@gmail.com wrote: And Pieren continues to add his opinion to the page. Not only mine. I'm still waiting at least a single example where a closed way for platforms is not an area (and rendering issue cannot be fixed by splitting the way for instance). You see, I'm even not asking a high ratio justifying a 2nd tag, just a single example (and not recently added) which could explain that the area=yes is not a workaround fixing rendering issues. Please forget a bit Mapnik. The case is rare enough to say that the assumption for the closed way is an area and adding the 2nd tag is a workaround. It's only what I'm saying on the wiki. Pieren ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] area=yes on polygones (was Block names)
On Tue, May 1, 2012 at 12:04 PM, Martin Koppenhoefer our data model should not need hacks like split the way to fix rendering issues. For me, the hack is to add a 2nd tag when it is not required in most (if not all) of the closed ways. Pieren ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] area=yes on polygones (was Block names)
01.05.2012 11:53, Pieren wrote: Not only mine. I'm still waiting at least a single example where a closed way for platforms is not an area How about that one? http://www.openstreetmap.org/browse/way/48923955 It's a public_transport=platform for busses. There's a building with ticket shops and toilets in the centre (not mapped yet). (and rendering issue cannot be fixed by splitting the way for instance). We could do that for highways and other examples, too: Always treat closed loops as an area, and model other loops by splitting the way. But that's not what we decided to do in those cases. Instead, we invented area=yes. Tobias ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] area=yes on polygones (was Block names)
On Tue, May 1, 2012 at 1:55 PM, Tobias Knerr o...@tobias-knerr.de wrote: 01.05.2012 11:53, Pieren wrote: How about that one? http://www.openstreetmap.org/browse/way/48923955 If I understand correctly this document (http://regiowiki.pnp.de/index.php/Zentraler_Omnibusbahnhof_Passau), it is serving 5 stations. So the name is incorrect and the way should be split for the 5 Bussteig. I would expect that the single way is for a single platform. It's a public_transport=platform for busses. There's a building with ticket shops and toilets in the centre (not mapped yet). Holes can be modelled as usual like we model holes in parks or buildings. But that's not what we decided to do in those cases. Instead, we invented area=yes. We invented area=yes for the ambiguous closed way tagged with highway=*. Spreading its usage on more features generates side effects like seeing more and more often the area=yes incorrectly attached on landuses, buildings, leisures, etc or even just as primary tag combined with name on closed ways (enough for rendering correctly the name in Mapnik). It is strange to see how easy it is accepted to split ways for silly route or boundary relations and rejected here. Pieren ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] area=yes on polygones (was Block names)
On Tue, May 1, 2012 at 7:55 AM, Tobias Knerr o...@tobias-knerr.de wrote: 01.05.2012 11:53, Pieren wrote: Not only mine. I'm still waiting at least a single example where a closed way for platforms is not an area How about that one? http://www.openstreetmap.org/browse/way/48923955 It's a public_transport=platform for busses. There's a building with ticket shops and toilets in the centre (not mapped yet). That's a closed way for a platform which *is* an area. It seems clear to me that the intent was not for this to represent a linear feature. If it were, the line would have been drawn down the center of the platform, not along the outside edge of it. (and rendering issue cannot be fixed by splitting the way for instance). We could do that for highways and other examples, too: Always treat closed loops as an area, and model other loops by splitting the way. That would have broken backward compatibility. ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] area=yes on polygones (was Block names)
On Tue, May 1, 2012 at 6:04 AM, Martin Koppenhoefer dieterdre...@gmail.com wrote: 2012/5/1 Pieren pier...@gmail.com: Not only mine. I'm still waiting at least a single example where a closed way for platforms is not an area (and rendering issue cannot be fixed by splitting the way for instance). our data model should not need hacks like split the way to fix rendering issues. It should be clear whether an object is an area or not (that's why I prefer explicit area=yes/no for cases which might be ambiguous). What about closed ways tagged with barrier=* and some other ambiguous *=* (e.g. barrier=hedge amenity=marketplace). I guess you could just put the amenity=marketplace on a multipolygon, and keep the barrier=hedge/area=no. So the official behavior of routers/renderers/etc on closed ways ambiguously not tagged as area=yes/no is undefined, though it is strongly suggested that data users assume area=no for highway=* and barrier=*. Maybe we even carve out an exception for highway=* and barrier=*, though I'd just as well we tag them explicitly too, whenever they are closed. Yes, I think this is a good solution. ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] area=yes on polygones (was Block names)
2012/4/30 Pieren pier...@gmail.com: I'm always standing in the contributor point of view. It is not the wiki (or better said our recommendations) to follow the osm2pqsql style file but the opposite. +1 especially when the main reaction is to say that mapnik/osm2pgsql will fail because the assumption is done on a key, not a key/value pair. +1, besides from the already named tags in this thread there is also leisure=track which is a nice example. Even it's wiki page says explicitly that it is not clear, whether this is an area or a linear feature, but there are asumptions that mapnik renders this as an area because the rest of the leisure tags are all areas (or nodes): http://wiki.openstreetmap.org/wiki/Tag:leisure%3Dtrack cheers, Martin ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] area=yes on polygones (was Block names)
On 27/04/12 20:11, Anthony wrote: On Fri, Apr 27, 2012 at 3:06 PM, Tobias Knerr o...@tobias-knerr.de wrote: Anthony wrote: If I were writing a renderer (actually, I am), I would assume that a closed way does not represent an area unless it a) has an always-area tag such as landuse or b) is tagged with area=yes. Your idea that some tags should make a closed way into an area by default, unless there's also a certain other tag (like area=no) present, is not established mapping style as far as I can tell. Currently, tags are either unambiguous, or the default assumption is not an area. Well that's a mistake that should be fixed. ___ I think that it's not a mistake. The idea of having different defaults for area= would not only keep programmers busy (they can do more beneficial things during the time wasted for this), it also confuses mappers. I (as a mapper) don't want to look up the default for every tag. Another point: A platform is a usually footway. They often work as footways as well, so I think that in this case they should be tagged highway=footway anyway. Different defaults for the area tag would create an ambiguity. This is just the first example of this inconsistency that comes to my mind. By the way - why are you tagging railway=platform? The public transport scheme has changed this to public_transport=platform more than a year ago. That's my two cents Marl ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] area=yes on polygones (was Block names)
Let's consider two well known examples: building=* = usually by default area=yes, a non-closed way may be considered as invalid(?) highway=* = usually by default area=no, even if a closed way A common default value would lead to either ~56M area=yes on buildings or ~52M area=no on highways while both could be done by useful, well thought, but different default assumptions. About your example, Marl: Am 28.04.2012 10:06, schrieb Marl: Another point: A platform is a usually footway. They often work as footways as well, so I think that in this case they should be tagged highway=footway anyway. Different defaults for the area tag would create an ambiguity. Yes, and in this special example, I would say, area=yes is required for correct tagging, as even the highway=footway should be interpreted as an area (it's not a footway around the platform). On the other hand, a fenced field is landuse=* (and in this respect implicitly area=yes) and barrier=fence (and here implicitly area=no), and that's fine. If you would use one common default value, tagging would require to override that, and therefore use two ways, as area=yes and area=no are not possible on the same way - and not possible to match to the correct tags they refer to. regards Peter ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] area=yes on polygones (was Block names)
28.04.2012 11:34, Peter Wendorff wrote: Let's consider two well known examples: building=* = usually by default area=yes, a non-closed way may be considered as invalid(?) Yes, it would be invalid. As documented in the wiki, the building key (ignoring building=entrance and the like) is for areas only. And this means that it isn't really a relevant example here. A common default value would lead to either ~56M area=yes on buildings or ~52M area=no on highways I assume that this is a misunderstanding, because I don't think anybody was suggesting that area=yes should be used together with tags that are unambiguous anyway. My suggestion, and current practice as far as I can tell, is: * If a tag can only be used on areas, or only on ways, you don't need an area tag. * If a tag can be used on both areas and ways, the default interpretation is that it is a way, and area=yes is required to make it an area. On the other hand, a fenced field is landuse=* (and in this respect implicitly area=yes) and barrier=fence (and here implicitly area=no), and that's fine. Actually, that particular style of using barrier=fence has always been a bit of a hack and it's probably not the best example of clean tagging. But since landuse cannot be used on ways, and barrier=fence cannot be used on areas (well, it can, but then it is treated as a this area is fenced attribute and not as a very wide fence), this is again not an example where area=yes or area=no is required at all. Tobias ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] area=yes on polygones (was Block names)
Am 28. April 2012 11:34 schrieb Peter Wendorff wendo...@uni-paderborn.de: On the other hand, a fenced field is landuse=* (and in this respect implicitly area=yes) and barrier=fence (and here implicitly area=no), and that's fine. I'd tag the way barrier=fence and create a multipolygon for the landuse with this way as outer. cheers, Martin ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] area=yes on polygones (was Block names)
I think we should decide the better way to map first, and then let the programmers prioritize the fix. Since programmers are already checking for always-area, it doesn't seem like a difficult fix. Are patches welcome? Patches welcome. As programmers, we need a complete machine-readable list of always-area keys and key=value's. -- Darafei Komяpa Praliaskouski OSM BY Team - http://openstreetmap.by/ xmpp:m...@komzpa.net mailto:m...@komzpa.net ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] area=yes on polygones (was Block names)
On Sat, Apr 28, 2012 at 6:04 AM, Tobias Knerr o...@tobias-knerr.de wrote: I assume that this is a misunderstanding, because I don't think anybody was suggesting that area=yes should be used together with tags that are unambiguous anyway. My suggestion, and current practice as far as I can tell, is: * If a tag can only be used on areas, or only on ways, you don't need an area tag. * If a tag can be used on both areas and ways, the default interpretation is that it is a way, and area=yes is required to make it an area. On the other hand, a fenced field is landuse=* (and in this respect implicitly area=yes) and barrier=fence (and here implicitly area=no), and that's fine. Actually, that particular style of using barrier=fence has always been a bit of a hack and it's probably not the best example of clean tagging. But since landuse cannot be used on ways, and barrier=fence cannot be used on areas (well, it can, but then it is treated as a this area is fenced attribute and not as a very wide fence), this is again not an example where area=yes or area=no is required at all. Now I'm confused. The wiki says that almost all the barrier=* types can be used on areas. So applying your rules above they would also require area=no. But this seems to be an exception? So it seems we're already at the point where we have to look up the default for every tag. And I'm not even sure where we can look up this default (apparently we have to look for an always-area tag somewhere in the code for your renderer? ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] area=yes on polygones (was Block names)
On Sat, Apr 28, 2012 at 7:38 AM, Komяpa m...@komzpa.net wrote: I think we should decide the better way to map first, and then let the programmers prioritize the fix. Since programmers are already checking for always-area, it doesn't seem like a difficult fix. Are patches welcome? Patches welcome. As programmers, we need a complete machine-readable list of always-area keys and key=value's. What specific program or programs are we looking at? Scanning the wiki it looks like usually-not-area would be less of a moving target. Otherwise almost every time someone adds a new amenity you have to add a new always-area tag. The usually-not-area would be junction=roundabout, barrier=*, highway=pedestrian, leisure=track, man_made=breakwater, man_made=groyne, man_made=pier, natural=cliff, and waterway=dam. I wouldn't even include public_transport=platform. In those few cases where you want a hole in the middle, use a multipolygon. Not sure what to make of sport=toboggan, sport=water_ski, or tourism=artwork. That would require more research. ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] area=yes on polygones (was Block names)
On Sat, Apr 28, 2012 at 7:59 AM, Anthony o...@inbox.org wrote: Scanning the wiki it looks like usually-not-area would be less of a moving target. Otherwise almost every time someone adds a new amenity you have to add a new always-area tag. The usually-not-area would be junction=roundabout, barrier=*, highway=pedestrian, leisure=track, man_made=breakwater, man_made=groyne, man_made=pier, natural=cliff, and waterway=dam. Make that highway=*. ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] area=yes on polygones (was Block names)
What specific program or programs are we looking at? Any program that needs to go from OSM data model to OGC-compatible one, having area object. That basically lists any database backend (osm2pgsql, osm2sqlite, nominatim...) and any converter like osm2shp/osm2ogr. The list of software that depends on these is significantly lareger, like nominatim, Mapnik, KothicJS, wikipedia integration project WIWOSM and most data consumers. tourism=artwork. That would require more research. The only problem that it requires research. Every coder that wants just to take OSM data has to do that research. Months of digging the wiki, basically. De facto list of always-area tags is present on http://svn.openstreetmap.org/applications/utils/export/osm2pgsql/default.style Anyone whining software authors should have a better always-area list or then software should be fixed should make that better list. Period. -- Darafei Komяpa Praliaskouski OSM BY Team - http://openstreetmap.by/ xmpp:m...@komzpa.net mailto:m...@komzpa.net ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] area=yes on polygones (was Block names)
On Sat, Apr 28, 2012 at 8:17 AM, Komяpa m...@komzpa.net wrote: What specific program or programs are we looking at? Any program that needs to go from OSM data model to OGC-compatible one, having area object. Well, my question is what program or programs are you requesting patches for. Presumably these are programs which you are maintaining, otherwise it's not your place to request patches for them. I certainly don't feel like doing work making a patch which winds up not being accepted. tourism=artwork. That would require more research. The only problem that it requires research. Every coder that wants just to take OSM data has to do that research. Months of digging the wiki, basically. De facto list of always-area tags is present on http://svn.openstreetmap.org/applications/utils/export/osm2pgsql/default.style Anyone whining software authors should have a better always-area list or then software should be fixed should make that better list. Period. First we need to agree on what needs to be fixed. Tobias says that no renderers or other applications working on OSM data should ever consider area=no. So obviously I wouldn't want to work on a patch for a program that he is maintaining, to fix it so that it considers area=no. ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] area=yes on polygones (was Block names)
On 27.04.2012 10:12, Pieren wrote: You have to know anyway if your feature can be either a closed way or an area and therefore need some special handling in your apps. Unfortunately, yes. I wish we already had a proper area primitive so this whole discussion would be obsolete. The question is then more to consider certain features as area or closed way by default. On this point, I'm always standing on the contributors side and wont ask them to add an unnecessary tag for 99.99% of the cases. Having to type area=yes less frequently is in the contributors' interest, sure. But having simple rules for defaults is also in the contributors' interest. Right now, we already have to distinguish three types of tags: * always area * always way * way unless area=yes is present. I simply do not think that the possibility to decrease of the number of tags is worth introducing area unless area=no is present in addition to these. Particularly because whether area or way is the default would depend on what is assumed to be more likely in reality. And people might easily have different assumptions here, making that kind of default non-obvious. Tobias ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] area=yes on polygones (was Block names)
On 4/28/2012 7:59 AM, Anthony wrote: Scanning the wiki it looks like usually-not-area would be less of a moving target. Otherwise almost every time someone adds a new amenity you have to add a new always-area tag. The usually-not-area would be junction=roundabout, barrier=*, highway=pedestrian, leisure=track, man_made=breakwater, man_made=groyne, man_made=pier, natural=cliff, and waterway=dam. There are also issues with multiple tags. For example tourism=attraction is usually an area, but on a railway=preserved that goes in a loop it's probably not. I don't think Mapnik handles an explicit area=no correctly here. ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] area=yes on polygones (was Block names)
On Sat, Apr 28, 2012 at 9:16 AM, Tobias Knerr o...@tobias-knerr.de wrote: Right now, we already have to distinguish three types of tags: * always area * always way * way unless area=yes is present. I simply do not think that the possibility to decrease of the number of tags is worth introducing area unless area=no is present in addition to these. Particularly because whether area or way is the default would depend on what is assumed to be more likely in reality. And people might easily have different assumptions here, making that kind of default non-obvious. I don't see how we'd be adding any more confusion by adding a fourth type. Right now if someone tags something as railway=platform they have to figure out whether it is always area (*) or way unless area=yes is present, and this is not at all obvious. Even more confusing are the barrier=* tags. I think they are of the type always way, but I'm not 100% sure about that. The wiki lists barrier=city_wall as being a way or an area. But I think by area they just mean closed way. Is barrier=city_wall always area (*), always way or way unless area=yes is present? How is someone supposed to figure this out? Allowing area=no provides a simple method of dealing with cases where you are unsure: just tag area=yes/no explicitly. (*) I note, here, that always area doesn't mean the way always represents an area, it means the way always represents an area when it is closed. ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] area=yes on polygones (was Block names)
Another example is amenity=marketplace. How am I supposed to know if this is always way, always area, or way unless area=yes is present? Which one is it? ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] area=yes on polygones (was Block names)
For the barrier=city_wall I in fact see way AND area as possible: A mid-age city wall of a bigger city may have walls of several meters width sometimes, that include corridors, stairways and more, as another building would. If I map a strip of grass as an area with a width of 1m, a city wall with 5m width is an area, too - that's sometimes similar in size than a usual house. I think, we should (!) introduce an area tag in the next API version, that allows the strict distinction between area and way by type, independent of tags. regards Peter Am 28.04.2012 15:39, schrieb Anthony: On Sat, Apr 28, 2012 at 9:16 AM, Tobias Knerro...@tobias-knerr.de wrote: Right now, we already have to distinguish three types of tags: * always area * always way * way unless area=yes is present. I simply do not think that the possibility to decrease of the number of tags is worth introducing area unless area=no is present in addition to these. Particularly because whether area or way is the default would depend on what is assumed to be more likely in reality. And people might easily have different assumptions here, making that kind of default non-obvious. I don't see how we'd be adding any more confusion by adding a fourth type. Right now if someone tags something as railway=platform they have to figure out whether it is always area (*) or way unless area=yes is present, and this is not at all obvious. Even more confusing are the barrier=* tags. I think they are of the type always way, but I'm not 100% sure about that. The wiki lists barrier=city_wall as being a way or an area. But I think by area they just mean closed way. Is barrier=city_wall always area (*), always way or way unless area=yes is present? How is someone supposed to figure this out? Allowing area=no provides a simple method of dealing with cases where you are unsure: just tag area=yes/no explicitly. (*) I note, here, that always area doesn't mean the way always represents an area, it means the way always represents an area when it is closed. ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] area=yes on polygones (was Block names)
Am 28. April 2012 16:10 schrieb Peter Wendorff wendo...@uni-paderborn.de: For the barrier=city_wall I in fact see way AND area as possible: A mid-age city wall of a bigger city may have walls of several meters width sometimes, that include corridors, stairways and more, as another building would. If I map a strip of grass as an area with a width of 1m, a city wall with 5m width is an area, too - that's sometimes similar in size than a usual house. +1, look here for example: http://maps.google.it/maps?q=roma+colomboll=41.874093,12.493483spn=0.000751,0.001321client=ubuntuchannel=csfb=1gl=ithq=roma+colomboradius=15000t=hz=20 cheers, Martin ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] area=yes on polygones (was Block names)
On Fri, Apr 27, 2012 at 2:53 AM, Tobias Knerr o...@tobias-knerr.de wrote: If a feature can be either a closed way or an area, the default interpretation should always be the closed way. Otherwise, you'd have to know arbitrary defaults for each type of object. You have to know anyway if your feature can be either a closed way or an area and therefore need some special handling in your apps. The question is then more to consider certain features as area or closed way by default. On this point, I'm always standing on the contributors side and wont ask them to add an unnecessary tag for 99.99% of the cases. Pieren ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] area=yes on polygones (was Block names)
On Thu, Apr 26, 2012 at 8:53 PM, Tobias Knerr o...@tobias-knerr.de wrote: Anthony wrote: On Wed, Apr 25, 2012 at 5:17 AM, Nathan Edgars II nerou...@gmail.com wrote: Where did I mention a renderer? If you draw a closed polygon with railway=platform, that's a continuous platform with a hole in the middle. There may be a few cases of such in real life at a complicated junction. If so, they should be tagged with area=no. area=no can be considered a sic!, but that tag should never have any actual effect. Effect on what? If I were writing a renderer, I would assume that a closed way railway=platform represented an area unless it was tagged area=no. So that's an effect. If a feature can be either a closed way or an area, the default interpretation should always be the closed way. Otherwise, you'd have to know arbitrary defaults for each type of object. A default set to the value which is correct 99.9% of the time is not arbitrary. Should defaults be documented somewhere? Absolutely. Should users of the data ignore reality because someone wrote something somewhere in the wiki? Absolutely not. ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] area=yes on polygones (was Block names)
On Fri, Apr 27, 2012 at 4:12 AM, Pieren pier...@gmail.com wrote: On Fri, Apr 27, 2012 at 2:53 AM, Tobias Knerr o...@tobias-knerr.de wrote: If a feature can be either a closed way or an area, the default interpretation should always be the closed way. Otherwise, you'd have to know arbitrary defaults for each type of object. You have to know anyway if your feature can be either a closed way or an area and therefore need some special handling in your apps. The question is then more to consider certain features as area or closed way by default. On this point, I'm always standing on the contributors side and wont ask them to add an unnecessary tag for 99.99% of the cases. I don't mind asking them to (hence I don't mind the wiki saying that they *should* do so). But I do mind if people take the fact that the wiki asks them to as an excuse not to add area=no in the other 0.01% of cases. Or, in RFC-speak. I would be fine with Users SHOULD add area=yes when mapping a railway platform as an area. Users MUST add area=no when mapping a railway platform with a closed way which does not represent an area. I'd prefer Users MAY add area=yes when mapping a railway platform as an area. Users MUST add area=no when mapping a railway platform with a closed way which does not represent an area. though. If the (nonexistent) specs say that area=no is the default for railway=platform closed ways, the (nonexistent) specs are broken. ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] area=yes on polygones (was Block names)
Am 27. April 2012 20:14 schrieb Anthony o...@inbox.org: A default set to the value which is correct 99.9% of the time is not arbitrary. how would you distinguish between default values and incomplete data/missing information? We could have a tag defaults_checked=area;surface;lanes;oneway;lit;width;... to show which defaults have been checked, and maybe have different default-schemes maintained by different people or for different topics. We could define default sets in the wiki, default_set_garry:version2=yes, with Versioning, so we can later amend the defaults_sets without bothering... But for simplicity when in doubt I'd set the tag explicitly. According to your estimations every default that is tagged explicitly is at least 0.1% better than not having it. ;-) cheers, Martin ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] area=yes on polygones (was Block names)
Op 27 apr. 2012 20:41 schreef Martin Koppenhoefer dieterdre...@gmail.com het volgende: Am 27. April 2012 20:14 schrieb Anthony o...@inbox.org: A default set to the value which is correct 99.9% of the time is not arbitrary. how would you distinguish between default values and incomplete data/missing information? The same way as you distinguish between old and current data: just not. Wait until some mapper sees that it's wrong. ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] area=yes on polygones (was Block names)
Anthony wrote: area=no can be considered a sic!, but that tag should never have any actual effect. Effect on what? On renderers or any other applications working with OSM data. If I were writing a renderer, I would assume that a closed way railway=platform represented an area unless it was tagged area=no. So that's an effect. If I were writing a renderer (actually, I am), I would assume that a closed way does not represent an area unless it a) has an always-area tag such as landuse or b) is tagged with area=yes. Your idea that some tags should make a closed way into an area by default, unless there's also a certain other tag (like area=no) present, is not established mapping style as far as I can tell. Currently, tags are either unambiguous, or the default assumption is not an area. Tobias ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] area=yes on polygones (was Block names)
On Fri, Apr 27, 2012 at 2:40 PM, Martin Koppenhoefer dieterdre...@gmail.com wrote: Am 27. April 2012 20:14 schrieb Anthony o...@inbox.org: A default set to the value which is correct 99.9% of the time is not arbitrary. how would you distinguish between default values and incomplete data/missing information? You can't distinguish between them. That's why defaults should be set to the value that's right most of the time. At least, they usually should (sometimes other considerations come into play, for example if the cost of guessing wrong on one side is much higher than the cost of guessing wrong on the other side). Note that I'm talking here about situations where presenting the end-user with unknown is not reasonable. I wouldn't suggest for a map to show default speed limits when nothing was provided. (On the other hand, a routing program probably is going to have to provide default speed limits when calculating the fastest path, and this is a situation where the value that's right most of the time might not be the best one to use.) We could have a tag defaults_checked=area;surface;lanes;oneway;lit;width;... to show which defaults have been checked, and maybe have different default-schemes maintained by different people or for different topics. We could define default sets in the wiki, default_set_garry:version2=yes, with Versioning, so we can later amend the defaults_sets without bothering... This doesn't sound reasonable. But for simplicity when in doubt I'd set the tag explicitly. I think that's probably a good idea for most tags, where the split is 80/20, or 60/40, or 90/10, or where the cost of getting it wrong is very high. For something like railway=platform I wouldn't bother. ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] area=yes on polygones (was Block names)
On Fri, Apr 27, 2012 at 3:06 PM, Tobias Knerr o...@tobias-knerr.de wrote: Anthony wrote: If I were writing a renderer, I would assume that a closed way railway=platform represented an area unless it was tagged area=no. So that's an effect. If I were writing a renderer (actually, I am), I would assume that a closed way does not represent an area unless it a) has an always-area tag such as landuse or b) is tagged with area=yes. Your idea that some tags should make a closed way into an area by default, unless there's also a certain other tag (like area=no) present, is not established mapping style as far as I can tell. Currently, tags are either unambiguous, or the default assumption is not an area. Well that's a mistake that should be fixed. ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] area=yes on polygones (was Block names)
While this is ongoing, Pieren continues to remove area=yes from railway=platform, which has been on the page since it was created in 2008: http://wiki.openstreetmap.org/w/index.php?title=Tag:railway%3Dplatformaction=history ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] area=yes on polygones (was Block names)
On Wed, Apr 25, 2012 at 5:17 AM, Nathan Edgars II nerou...@gmail.com wrote: Where did I mention a renderer? If you draw a closed polygon with railway=platform, that's a continuous platform with a hole in the middle. There may be a few cases of such in real life at a complicated junction. If so, they should be tagged with area=no. ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] area=yes on polygones (was Block names)
Anthony wrote: On Wed, Apr 25, 2012 at 5:17 AM, Nathan Edgars II nerou...@gmail.com wrote: Where did I mention a renderer? If you draw a closed polygon with railway=platform, that's a continuous platform with a hole in the middle. There may be a few cases of such in real life at a complicated junction. If so, they should be tagged with area=no. area=no can be considered a sic!, but that tag should never have any actual effect. If a feature can be either a closed way or an area, the default interpretation should always be the closed way. Otherwise, you'd have to know arbitrary defaults for each type of object. Tobias ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] area=yes on polygones (was Block names)
The german article still has the recommendation of adding area=yes. One of the biggest problems in the wiki is the fact, that very often articles in different languages are not really translations, but different articles. As the tag railway=platform is applicable to areas as well, according to articles in all languages, and therefore area=yes shouldn't be necessary on closed ways, I will update this note in the german article in accordance with the updated english article. Martin 2012/4/25 Pieren pier...@gmail.com: On Wed, Apr 25, 2012 at 3:46 AM, Nathan Edgars II nerou...@gmail.com wrote: It's not highway only. For example, it can be used on railway=platform: http://www.openstreetmap.org/browse/way/94063273 or man_made=pier: http://www.openstreetmap.org/browse/way/71124853 Thanks for pointing that out. I see that silently, the meaning of the tag area has been modified by certain people on the wiki. I modified the wiki about platform: http://wiki.openstreetmap.org/wiki/Tag:railway%3Dplatform We cannot accept that the tag area=yes is required for all polygons. This has never been the case. It was introduced only when the main tag about a closed loop was non-deterministic (tracing a centre line or a perimeter). We don't do that for car parks, buildings, etc. I don't see why we should create an exception for railway platforms. Pieren ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] area=yes on polygones (was Block names)
On 4/25/2012 3:39 AM, Pieren wrote: On Wed, Apr 25, 2012 at 3:46 AM, Nathan Edgars IInerou...@gmail.com wrote: It's not highway only. For example, it can be used on railway=platform: http://www.openstreetmap.org/browse/way/94063273 or man_made=pier: http://www.openstreetmap.org/browse/way/71124853 Thanks for pointing that out. I see that silently, the meaning of the tag area has been modified by certain people on the wiki. I modified the wiki about platform: http://wiki.openstreetmap.org/wiki/Tag:railway%3Dplatform We cannot accept that the tag area=yes is required for all polygons. This has never been the case. It was introduced only when the main tag about a closed loop was non-deterministic (tracing a centre line or a perimeter). We don't do that for car parks, buildings, etc. I don't see why we should create an exception for railway platforms. Because a railway platform is usually drawn as a single line (as is a pier). Omitting area=yes gives a hole in the middle. ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] area=yes on polygones (was Block names)
On Wed, Apr 25, 2012 at 10:43 AM, Nathan Edgars II nerou...@gmail.com wrote: Because a railway platform is usually drawn as a single line (as is a pier). Omitting area=yes gives a hole in the middle. Sounds tagging for the renderer... Pieren ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] area=yes on polygones (was Block names)
miau. OSM does not have area object, thus it needs something to mark object as polygon. There are some tags that insist that a line/relation is filled inside. These are area=yes and type=multipolygon. All the other tags may mean either line or a polygon depending on context. Sometimes context isn't clear. (Is a circular highway a roundabout or a filled square?..) It is rather distinct that highway=*, railway=* are linear usually, and that landuse=*, amenity=*, shop=*, natural=*, area:highway=* are polygonal. However, there are some cases when it's not true, like the platform. We either need a complete machine-readable list of tags that are polygons or lines, or need to tag each object separately. For now I see just the second approach being used; telling that is't invalid without providing any reasonable fallback is a bad idea. Currently used list can be found at http://svn.openstreetmap.org/applications/utils/export/osm2pgsql/default.style -- Darafei Komяpa Praliaskouski OSM BY Team - http://openstreetmap.by/ xmpp:m...@komzpa.net mailto:m...@komzpa.net ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] area=yes on polygones (was Block names)
On 4/25/2012 4:53 AM, Pieren wrote: On Wed, Apr 25, 2012 at 10:43 AM, Nathan Edgars IInerou...@gmail.com wrote: Because a railway platform is usually drawn as a single line (as is a pier). Omitting area=yes gives a hole in the middle. Sounds tagging for the renderer... Where did I mention a renderer? If you draw a closed polygon with railway=platform, that's a continuous platform with a hole in the middle. There may be a few cases of such in real life at a complicated junction. ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] area=yes on polygones (was Block names)
On Wed, Apr 25, 2012 at 11:05 AM, Komяpa m...@komzpa.net wrote: OSM does not have area object, not yet (maybe in API0.7) thus it needs something to mark object as polygon. No. Most of the polygons do not require a tag area (amenity, building, landuse, leisure, landuse). There are some tags that insist that a line/relation is filled inside. These are area=yes and type=multipolygon. Sorry, I don't understand what you try to say here. type=multipolygon is about relations or I miss something ? Sometimes context isn't clear. (Is a circular highway a roundabout or a filled square?..) Agree. This case is why the tag area has been created. It is rather distinct that highway=*, railway=* are linear usually, Hmm... railway yes, platform not sure. As many other features, platform can be represented by a node, a line or a polygon. This just depends on the contributor and his mapping level (and source accuracy and/or motivation). Same issue with people symbolizing rivers with a line and others with a polygon (and a centre line). We either need a complete machine-readable list of tags that are polygons or lines, or need to tag each object separately. For now I see just the second approach being used; telling that is't invalid without providing any reasonable fallback is a bad idea. Currently used list can be found at http://svn.openstreetmap.org/applications/utils/export/osm2pgsql/default.style A closed loop tagged highway requires an additional information. Until a new element type polygon is created in the futur, the area=yes makes sens here. But a closed loop for railway=platform does not require any thing more than the geometry (a closed way tagged railway=platform is always a polygon. Are you asking contributors to specially tag an object just to avoid some work in osm2pgsql (detect if the way tagged railway=platform is closed or not) ? Pieren ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] area=yes on polygones (was Block names)
On Apr 25, 2012 1:54 AM, Pieren pier...@gmail.com wrote: On Wed, Apr 25, 2012 at 10:43 AM, Nathan Edgars II nerou...@gmail.com wrote: Because a railway platform is usually drawn as a single line (as is a pier). Omitting area=yes gives a hole in the middle. Sounds tagging for the renderer... If it's not incorrect, and is more specific than omission would be, is that a bad thing? In this instance specifically, I'm inclined to say no. ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
