Re: [Tagging] tagging the multipolygon model (was landuse and military)
2009/10/15 sly (sylvain letuffe) li...@letuffe.org: On jeudi 15 octobre 2009, Martin Koppenhoefer wrote: For the lake in the forest: do you agree that someone would say: the lake (pond) is in the forest? Like a way in the forest, which doesn't have trees growing on it, but still is in the forest. It is not excluded. That's a human language matter. I don't think it's good to stick a data model to verbs and words. it's not purely about language. It is about definitions, and the way you are looking at things. Between them, there should be interpretation, understanding, and questions answering. That is to say, programs. infomationstechnology-centric point of view Case of the lake in the forest, you could imagine multi-question to answer : - what surface is this forest ? Suppose I'm a wood lumber producer, I've got statitics about mean trees per square km. I'll surely want to exclude the lake's surface, as well as any road's surface going thru. - is the lake in a forest ? I suppose here I want to know if I can reach the lake by transporting my boat through grass fields. I'm not sure if someone counts the surface of forests he doesn't usually include lakes that belong to the forest. If you want to get the surface of tree-planted areas, you still will have to subtract streets, and potentially other included areas where there are no trees. - Probably you are right and it is a better approach to exclude lakes and even small ponds from the forest (the street-problem remains though). cheers, Martin ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] tagging the multipolygon model (was landuse and military)
On vendredi 16 octobre 2009, Emilie Laffray wrote: 2009/10/16 Martin Koppenhoefer dieterdre...@gmail.com +1, I agree. Inside a landuse=residential we could than map the different surfaces. I'd suggest to use the key surface for the ground-cover, or is there a problem with it? Having a ground-cover tag would be perfect. What about every thing but boundary is ground-cover surface ? (I haven't checked the whole map features) -- sly Sylvain Letuffe li...@letuffe.org qui suis-je : http://slyserv.dyndns.org ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] tagging the multipolygon model (was landuse and military)
On Fri, Oct 16, 2009 at 2:16 PM, Ben Laenen benlae...@gmail.com wrote: It obviously failed at that completely. The most used tags (landuse=residential, industrial, farm, commercial, military, retail...) don't give any detail about ground cover. It has become so bad that I don't see a way to even try to fix this with the landuse tag. It has to go back to the drawing board without thinking about tags that are in use today. Ben It doesn't fail so much because most of the time, landuse values are exclusive (residential, industrial, forest, etc). It is already enough complicated to add polygones or multipolygones for landuse. We can see that this is only done in countrysides or small urban areas but not in towns/cities. We cannot ask people to create a second polygon which will most of the time be a copy of the landuse : land covered by buildings used for residential or land covered by trees used for trees farm. I think we should better enforce landuse to be exclusive by removing the non-exclusive values like military. Pieren ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] tagging the multipolygon model (was landuse and military)
On Fri, Oct 16, 2009 at 9:25 AM, Ben Laenen benlae...@gmail.com wrote: Residential isn't exclusive at all. Not to say that what it's actually used for in OSM can have different meanings amongst different mappers. You'll find many parks in OSM for example inside a residential polygon. I've never seen holes in a landuse=residential polygon at locations where shops are. By far most uses I've seen for landuse=residential are for areas which are generally used for where people live, and usually have entire villages or cities inside one polygon. That's not ground cover, that's telling what the area is used for. Proper ground cover would have no such thing as a residential area. It would have tags for building (and subtags for what kind of building it is), or garden. Well then ground cover isn't what we need. We need land use. Land use is generally studied on a parcel by parcel basis. The fact that OSM mappers make these huge polygons which cover entire towns is fine, as an approximation, but ultimately we should be striving to get down to the parcel level, or even more detailed. ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] tagging the multipolygon model (was landuse and military)
On Fri, Oct 16, 2009 at 9:54 AM, Ben Laenen benlae...@gmail.com wrote: Anthony wrote: Well then ground cover isn't what we need. We need land use. Land use is generally studied on a parcel by parcel basis. The fact that OSM mappers make these huge polygons which cover entire towns is fine, as an approximation, but ultimately we should be striving to get down to the parcel level, or even more detailed. A typical example of a land use map: http://cityofypsilanti.com/maps/images/mastermap2006www.jpg Well, we need both land use *and* ground cover. The former telling what people use the area for, the latter telling what you can actually see on the ground. The former says park, the latter says grass, trees... for the same area. University vs buildings, grass, garden, trees... Residential vs buildings, gardens, parks, construction sites... Military vs buildings, woods, crop fields, heath, meadows... etc Maybe we need ground cover. I'm not convinced of it, but maybe we do. But this is a completely different problem - it's the opposite problem of landuse=*, in fact. Instead of using one tag for multiple things, we're using lots of tags (amenity=*, man_made=*, natural=*, leisure=*) for what you're arguing to be one thing (as I said, I'm not yet convinced). ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] tagging the multipolygon model (was landuse and military)
On Fri, Oct 16, 2009 at 3:36 PM, Anthony o...@inbox.org wrote: On Fri, Oct 16, 2009 at 9:31 AM, Anthony o...@inbox.org wrote: Land use is generally studied on a parcel by parcel basis. A typical example of a land use map: http://cityofypsilanti.com/maps/images/mastermap2006www.jpg Here is another typical example of a land use map: http://www.ifen.fr/typo3temp/pics/3e9fb4d1ad.jpg Just to say that we have different scales of land use. It can be country wide or at city level. It is not a reason to use different tags. Pieren ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] tagging the multipolygon model (was landuse and military)
2009/10/14 sly (sylvain letuffe) li...@letuffe.org: In the holes continuity, it as been proposed that an area representing something inside another area would still be part of a multipolygon relation but with it's own tags. no, this is not the case. Multipolygon says: the inner part is NOT part of the outer polygon. If it is part just don't put a multipolygon-relation (standard-case). this sounds great, requesting the surface of the big area is strait forward, rendering become easy (no which one is over which one), such a puzzle makes it easy to find problems, etc. no, this is a case to be solved continuously - usually if one polygon is entirely inside another the smaller one should be rendered above: this should be generally solved by the renderers. Also, it can be better in some cases not to use a solid fill but just an outline that is rendered above the fills. But, this becomes harder and harder for the mapper. A big forest containing thousands lakes ? a landuse=residential containing park, cimetary, etc. ? I fear not every one is gone a make the effort. And after all, is it at all needed ? let the mappers decide. In the area inside area case (not the partially overlapping areas case) We can resonably imagine that if a mapper has added such an area inside another, then either : - they can be both (a military area and a forest) - they can't be both (a lake and a forest) well, even in the case lake inside a forest I'm not sure, if the forest stops where there is the lake. Probably you can consider the lake also part of the forest (when it's small), or to give a different example: elementary school inside a residential area. Usually those would be considered to be part of the residential area. Maybe if we just define/explain/(do our best not to create same key incompatibility, juste like this boundary=military propose to replace the ambiguous landuse=military for some cases) Same for natural, then what we've left ? amenity? Finally almost all tags can become areas. A lake inside a forest, is not a forest sure? A cimetary inside a residential is not a residential +1 cheers, Martin ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] tagging the multipolygon model (was landuse and military)
Martin Koppenhoefer wrote: well, even in the case lake inside a forest I'm not sure, if the forest stops where there is the lake. Probably you can consider the lake also part of the forest (when it's small), or to give a different example: elementary school inside a residential area. Usually those would be considered to be part of the residential area. I disagree. A school site with it's buildings, playgrounds, sports fields etc can add up to a big area. Someone may want to do some calculations based on these areas. They should be as accurate as possible. I'm in the process of editing the existing residential areas in my town to go around these. It certainly makes a difference. Maybe if we just define/explain/(do our best not to create same key incompatibility, juste like this boundary=military propose to replace the ambiguous landuse=military for some cases) Same for natural, then what we've left ? amenity? Finally almost all tags can become areas. A lake inside a forest, is not a forest sure? Yes A cimetary inside a residential is not a residential +1 Then how can you include schools? Cheers Dave F. ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] tagging the multipolygon model (was landuse and military)
On jeudi 15 octobre 2009, Martin Koppenhoefer wrote: no, this is not the case. Multipolygon says: the inner part is NOT part of the outer polygon. I didn't say that ;-) I said : an area representing something inside another area would still be part of a multipolygon relation (I assumed people discussing this with me are familiar with the (advanced) multipolygon proposal and have assumed I was talking about an inner role in this case.) let the mappers decide. So we do agree. My point was to stop or not to stop harrassing mappers that do not include inner polygons. and/or not updating the wiki acordingly, giving the choice, mentionning that solution. We could let decide, but give clues about what's for what. -- sly Sylvain Letuffe li...@letuffe.org qui suis-je : http://slyserv.dyndns.org ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] tagging the multipolygon model (was landuse and military)
On jeudi 15 octobre 2009, Martin Koppenhoefer wrote: For the lake in the forest: do you agree that someone would say: the lake (pond) is in the forest? Like a way in the forest, which doesn't have trees growing on it, but still is in the forest. It is not excluded. That's a human language matter. I don't think it's good to stick a data model to verbs and words. Between them, there should be interpretation, understanding, and questions answering. That is to say, programs. The data model should be able to answer maximum human questions (with programs) Case of the lake in the forest, you could imagine multi-question to answer : - what surface is this forest ? Suppose I'm a wood lumber producer, I've got statitics about mean trees per square km. I'll surely want to exclude the lake's surface, as well as any road's surface going thru. - is the lake in a forest ? I suppose here I want to know if I can reach the lake by transporting my boat through grass fields. ... -- sly Sylvain Letuffe li...@letuffe.org qui suis-je : http://slyserv.dyndns.org ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] tagging the multipolygon model (was landuse and military)
On Thu, Oct 15, 2009 at 12:27 PM, Dave F. dave...@madasafish.com wrote: Anthony wrote: What happens when there's a section of forest which people are using as their residence? No matter what the size, I see these as mutually exclusive. In other words they can't both occur in the same place. I fully agree with you - as I said, I think landuse=forest should be reserved for things like tree farms, where the *use* of the land is growing trees. Whether they get mapped like that is up to the mapper depending time/fussiness. If there was an easyway to put holes in areas it would encourage mappers to do it. add a fixme=create_hole tag and a bot could go around fixing them... ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
