Re: [Tagging] Relation for saying x is attached to y?
On 05.09.2010 09:23, Steve Bennett wrote: On Sat, Sep 4, 2010 at 6:58 PM, Peter Wendorff wendo...@uni-paderborn.de wrote: I'm sure, there has to be a way for renderers to collapse parallel ways to one - without explicit tagging in the database. The railway example is only one of more examples. Right, to do this well we'd really need to work out some good use cases. Incidentally, a middle ground option would be to have an relation that indicates that the two tracks are indeed parallel and form a pair. A renderer could use that information to compute a middle line when required. If collapsing takes into account the number of collapsed tracks to consider it for the signature in the map - even better. The signature? What do you mean? Well - I fear, I used the word with one of meanings it has in German - but probably not in English http://de.wikipedia.org/wiki/Signatur_%28Kartographie%29 A Signatur - other meanings can be translated to the English signature - in the context of cartography is the style a map feature is visualized - an icon, the style and colors of a line and so on. ;) What's the English word for that? Regards Peter ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Relation for saying x is attached to y?
On 04.09.2010 07:00, Steve Bennett wrote: Any existing renderer would not render C at all. Any renderer (or other tool) that added support for railway=train_line, would presumably also add support for the relation. As that's right from the applications point of view, keep in mind the need for mapping people. Artificial, virtual lines like these are good for the renderers - but complicated in editor software: I have 1) to know about the train_line concept 2) to move this way additionally I'm sure, there has to be a way for renderers to collapse parallel ways to one - without explicit tagging in the database. The railway example is only one of more examples. If collapsing takes into account the number of collapsed tracks to consider it for the signature in the map - even better. regards Peter ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Relation for saying x is attached to y?
On 04/09/2010 06:53, Steve Bennett wrote: On Fri, Sep 3, 2010 at 2:37 AM, M∡rtin Koppenhoefer dieterdre...@gmail.com wrote: so you are talking about rendering? Primarily, yes. But could be useful for other applications. For example, to do public transport routing, you would want to operate at the level of the train line, not at the level of an individual track. If you mean which train do I catch to get from A to B the the presence of the tracks says nothing about the route of the train services. On the other hand if you are working for the train (infrastructure) company planning a train path from A to B you will need to know all the details about the individual tracks and where they connect. Multiple train tracks are definitely conceptually different to multiple lanes on a motorway. In a car on the motorway you can change lanes wherever you like - all the lanes are normally equivalent to each other (exceptions include crawler lanes, carpool lanes etc etc). Trains are only able to change tracks where there are points/switches. Colin ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Relation for saying x is attached to y?
On Fri, Sep 3, 2010 at 2:37 AM, M∡rtin Koppenhoefer dieterdre...@gmail.com wrote: so you are talking about rendering? Primarily, yes. But could be useful for other applications. For example, to do public transport routing, you would want to operate at the level of the train line, not at the level of an individual track. A rendering hint that these two ways might be rendered as one in lower zooms? Yes, that's a primary use case. Do you want to have three ways in OSM to represent 2 tracks? Yes, but this is just one example. Lanes of roads is another. Perhaps someone will think of other examples. Steve ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Relation for saying x is attached to y?
On Fri, Sep 3, 2010 at 9:59 AM, John F. Eldredge j...@jfeldredge.com wrote: The problem is that, even if you have a tag on the shared way indicating use this only for zoom X or below, and tags on the separate ways saying use this only for zoom Y and above, there are likely to be some rendering programs that will show all three ways, leading to confusion. Let's not assume all implementations of any new idea will be faulty :) Similarly, if the possibility that an existing renderer will badly render some new tag is considered a blocker, then OSM is essentially already dead. We're not at the stage where backward compatibility is essential, IMHO. That said, I can think of ways to implement such an idea while maintaining backward compatibility. Let's say three are three ways: A: north bound train track B: south bound train track C: placed between A and B, to represent the higher level abstraction of the train line, as opposed to the individual tracks. A: railway=rail B: railway=rail C: railway=train_line (or some new, unused tag) relation Z: type=grouping grouping=train_line Any existing renderer would not render C at all. Any renderer (or other tool) that added support for railway=train_line, would presumably also add support for the relation. Remember, this is all just a hypothetical example, not just about train tracks. I imagine there are other examples, though I don't have any in mind atm. Steve ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Relation for saying x is attached to y?
On Tue, Aug 31, 2010 at 1:46 AM, Phil! Gold phi...@pobox.com wrote: There is a proposal for a tracks= tag: http://wiki.openstreetmap.org/wiki/Proposed_features/Multiple_Tracks Ok, two points: 1) That's a mechanism for only having a single way, and coding information about the number of tracks. I'm talking about mapping both tracks, but also mapping a single way which *represents* both tracks. 2) A generic mechanism would make life easier for reusers of data anyway. Steve ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Relation for saying x is attached to y?
2010/9/2 Steve Bennett stevag...@gmail.com: On Tue, Aug 31, 2010 at 1:46 AM, Phil! Gold phi...@pobox.com wrote: There is a proposal for a tracks= tag: http://wiki.openstreetmap.org/wiki/Proposed_features/Multiple_Tracks Ok, two points: 1) That's a mechanism for only having a single way, and coding information about the number of tracks. I'm talking about mapping both tracks, but also mapping a single way which *represents* both tracks. so you are talking about rendering? A rendering hint that these two ways might be rendered as one in lower zooms? Or what do you intent with mapping both tracks, but _also_ mapping a single way which *represents* both tracks.? Do you want to have three ways in OSM to represent 2 tracks? cheers, Martin ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Relation for saying x is attached to y?
The problem is that, even if you have a tag on the shared way indicating use this only for zoom X or below, and tags on the separate ways saying use this only for zoom Y and above, there are likely to be some rendering programs that will show all three ways, leading to confusion. ---Original Email--- Subject :Re: [Tagging] Relation for saying x is attached to y? From :mailto:stevag...@gmail.com Date :Thu Sep 02 07:45:41 America/Chicago 2010 On Tue, Aug 31, 2010 at 1:46 AM, Phil! Gold phi...@pobox.com wrote: There is a proposal for a tracks= tag: http://wiki.openstreetmap.org/wiki/Proposed_features/Multiple_Tracks Ok, two points: 1) That's a mechanism for only having a single way, and coding information about the number of tracks. I'm talking about mapping both tracks, but also mapping a single way which *represents* both tracks. 2) A generic mechanism would make life easier for reusers of data anyway. Steve ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging -- John F. Eldredge -- j...@jfeldredge.com Reserve your right to think, for even to think wrongly is better than not to think at all. -- Hypatia of Alexandria ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Relation for saying x is attached to y?
2010/8/31 Tom Chance t...@acrewoods.net: Based on this discussion, it seems that the best advice to put on my proposal for power generators is: - use site relations where the power=generator objects don't obviously overlap with the buildings they relate to, particularly where you are dealing with a cluster of nearby objects it might be useful to suggest roles in your proposal for the different objects in the site relation (beside label there is not much yet) cheers, Martin ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Relation for saying x is attached to y?
On Mon, Aug 30, 2010 at 2:09 AM, Sebastian Klein basti...@googlemail.com wrote: Isn't it kind of obvious, that a photovoltaic type power generator is located on top of the building rather than inside or below? You may assume a basic level of intelligence from the user of the data and add only information that has more than one option. E.g. is the post box attached to a wall or does it stand on its own? In this example you would not need a relation, since the post box node can simply be joined with the building way. Assuming a basic level of intelligence really harms machine reuse of data. Even things that seem really obvious to a person can be complex, tedious, and error-prone to code. Using relations and other tags to make relationships very explicit makes reusing data much easier. One example is bus stops. When a bus stop is near a way, it's obvious to a person what that means - but pretty tricky for a program to use for routing. Steve ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Relation for saying x is attached to y?
On 8/30/10 9:06 AM, M∡rtin Koppenhoefer wrote: 2010/8/29 Pierenpier...@gmail.com: On Sun, Aug 29, 2010 at 11:37 AM, Nathan Edgars IInerou...@gmail.com wrote: Perhaps a site relation? I'm not sure it's necessary; any application that needs that information can calculate whether the polygons overlap. Yes, the topology shows what is inside or outside the polygon. And you can use the tag layer to say what is on the top of what. +1, but site-relations might still be useful in the context of power generators. There are situations where the single objects do not overlap but are side a side, for example you might have 3 generators with 3 chimneys and want to model which chimney is connected to which generator. i'd lean towards site relations being useful because i think that the computational complexity of doing lots of polygon intersections is being underestimated. yes, for small bounding boxes it's ok, but consider if you needed to do it on a larger scale, it'd make certain tasks completely unreasonable (i'm not sure what those tasks might be yet, haven't thought about it.) richard ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Relation for saying x is attached to y?
On Mon, Aug 30, 2010 at 11:18 PM, Richard Welty rwe...@averillpark.net wrote: i'd lean towards site relations being useful because i think that the computational complexity of doing lots of polygon intersections is being underestimated. yes, for small bounding boxes it's ok, but consider if you needed to do it on a larger scale, it'd make certain tasks completely unreasonable (i'm not sure what those tasks might be yet, haven't thought about it.) Yep. Polygon collisions can also be accidental, like when two objects from slightly different sources (say one gps, one aerial imagery) are near each other. A relation is a very explicit statement. Other generic relation types that would be very useful: - these objects are mutually accessible by foot (to avoid having to invent artificial foot paths in order to get good routing) - these objects express the same thing as that object but in more detail (eg, one line representing a pair or more of train lines) - these objects are one (like a very generic multipolygon, could also work to form multiways) Steve ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Relation for saying x is attached to y?
2010/8/30 Steve Bennett stevag...@gmail.com: Yep. Polygon collisions can also be accidental, like when two objects from slightly different sources (say one gps, one aerial imagery) are near each other. I'd consider this mapping failure actually. More than believing in gps- and imagery-precision the mapper should care about topology. Other generic relation types that would be very useful: - these objects are mutually accessible by foot (to avoid having to invent artificial foot paths in order to get good routing) you can do this with the area-relation (not restricted but restrictable to foot) - these objects express the same thing as that object but in more detail (eg, one line representing a pair or more of train lines) interesting, but maybe difficult to do. - these objects are one (like a very generic multipolygon, could also work to form multiways) can't you already do this with current multipolygons? (OK, only for areas, for ways there are routes). cheers, Martin ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Relation for saying x is attached to y?
2010/8/30 M∡rtin Koppenhoefer dieterdre...@gmail.com: - these objects express the same thing as that object but in more detail (eg, one line representing a pair or more of train lines) in this actual example you don't need relations but can do as with streets (lanes-tag). I'm not sure on the best syntax though: should it be tracks=4 or lanes=4? The latter is less correct regarding the language but doesn't require additional tags. cheers, Martin ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Relation for saying x is attached to y?
* M∡rtin Koppenhoefer dieterdre...@gmail.com [2010-08-30 17:40 +0200]: 2010/8/30 M∡rtin Koppenhoefer dieterdre...@gmail.com: - these objects express the same thing as that object but in more detail (eg, one line representing a pair or more of train lines) in this actual example you don't need relations but can do as with streets (lanes-tag). I'm not sure on the best syntax though: should it be tracks=4 or lanes=4? The latter is less correct regarding the language but doesn't require additional tags. There is a proposal for a tracks= tag: http://wiki.openstreetmap.org/wiki/Proposed_features/Multiple_Tracks -- ...computer contrarian of the first order... / http://aperiodic.net/phil/ PGP: 026A27F2 print: D200 5BDB FC4B B24A 9248 9F7A 4322 2D22 026A 27F2 --- -- Education is a better safeguard of liberty than a standing army. -- Edward Everett --- -- ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
[Tagging] Relation for saying x is attached to y?
Hi there, I want a way of creating an object for an energy generator and then saying this is on top of / inside this building object. Here is an example of one such object: http://www.openstreetmap.org/browse/way/35802300 I checked on the wiki page and couldn't see any established or proposed uses of relations for this purpose. Am I missing one, has this been discussed before? http://wiki.openstreetmap.org/wiki/Relations Regards, Tom -- http://tom.acrewoods.net http://twitter.com/tom_chance ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Relation for saying x is attached to y?
On Sun, Aug 29, 2010 at 5:32 AM, Tom Chance t...@acrewoods.net wrote: Hi there, I want a way of creating an object for an energy generator and then saying this is on top of / inside this building object. Here is an example of one such object: http://www.openstreetmap.org/browse/way/35802300 I checked on the wiki page and couldn't see any established or proposed uses of relations for this purpose. Am I missing one, has this been discussed before? http://wiki.openstreetmap.org/wiki/Relations Regards, Tom Perhaps a site relation? I'm not sure it's necessary; any application that needs that information can calculate whether the polygons overlap. ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Relation for saying x is attached to y?
On Sun, Aug 29, 2010 at 11:37 AM, Nathan Edgars II nerou...@gmail.comwrote: Perhaps a site relation? I'm not sure it's necessary; any application that needs that information can calculate whether the polygons overlap. Yes, the topology shows what is inside or outside the polygon. And you can use the tag layer to say what is on the top of what. Pieren ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] Relation for saying x is attached to y?
Tom Chance wrote: Hi there, I want a way of creating an object for an energy generator and then saying this is on top of / inside this building object. Here is an example of one such object: http://www.openstreetmap.org/browse/way/35802300 I checked on the wiki page and couldn't see any established or proposed uses of relations for this purpose. Am I missing one, has this been discussed before? http://wiki.openstreetmap.org/wiki/Relations Isn't it kind of obvious, that a photovoltaic type power generator is located on top of the building rather than inside or below? You may assume a basic level of intelligence from the user of the data and add only information that has more than one option. E.g. is the post box attached to a wall or does it stand on its own? In this example you would not need a relation, since the post box node can simply be joined with the building way. If there is something notable about the object, you could also start with a note=* tag that describes the interesting features. If there are more advanced tagging schemes in the future, other mappers can apply it without visiting the place again. Sebastian ___ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
