Re: [OSM-talk] [Fwd: Re: zones for motorway/in town/outof town?]
Am Thursday 21 May 2009 schrieb Radomir Cernoch: Guenther Meyer píše v Čt 21. 05. 2009 v 00:49 +0200: Am Wednesday 20 May 2009 schrieb Radomir Cernoch: ...but you would need some kind of gis database/functions to evaluate the polygon data. the easy way of reading just keys and values like with most of the other features in the osm database would not be possible. I have read somewhere (a few weeks ago) that querying whether a point lies in a country can be done quickly. I was assuming that the same should be possible for any polygon. However I am not aware of technical details. yes - if you can make use of a database with geospatial extension like postgis. there you have functions to find out easily if a point or a line (which streets are) lies inside a given polygon. I you don't have those functions, I don't know if this is possible. It may be, but this would be a very complex thing... signature.asc Description: This is a digitally signed message part. ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] [Fwd: Re: zones for motorway/in town/outof town?]
Guenther Meyer píše v Čt 21. 05. 2009 v 09:02 +0200: yes - if you can make use of a database with geospatial extension like postgis. there you have functions to find out easily if a point or a line (which streets are) lies inside a given polygon. I you don't have those functions, I don't know if this is possible. It may be, but this would be a very complex thing... Thank you for your explanation. Would it be then possible to ask questions like: Is the point at (x,y) inside any polygon, which has tag 'z'? Or even something like a JOIN of the point itself with the polygon: Give me all points in bbox (a,b,c,d) and the value of 'zone:xxx' of an encompassing polygon, if they lie in some? Sorry for many questions, but I do not want to promote an idea without knowing that it's feasible... Thanks in advance, Radek Černoch ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] [Fwd: Re: zones for motorway/in town/outof town?]
Am Thursday 21 May 2009 schrieb Radomir Cernoch: Guenther Meyer píše v Čt 21. 05. 2009 v 09:02 +0200: yes - if you can make use of a database with geospatial extension like postgis. there you have functions to find out easily if a point or a line (which streets are) lies inside a given polygon. I you don't have those functions, I don't know if this is possible. It may be, but this would be a very complex thing... Thank you for your explanation. Would it be then possible to ask questions like: Is the point at (x,y) inside any polygon, which has tag 'z'? Or even something like a JOIN of the point itself with the polygon: Give me all points in bbox (a,b,c,d) and the value of 'zone:xxx' of an encompassing polygon, if they lie in some? with or without gis functions? with those functions this all is possible. without, searching for points inside a bbox or circle is relatively easy, finding a point inside a polygon is maybe also doable with some more effort. Sorry for many questions, but I do not want to promote an idea without knowing that it's feasible... I'm not a gis expert, maybe here are people who know this better... what is your idea? signature.asc Description: This is a digitally signed message part. ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] [Fwd: Re: zones for motorway/in town/ outof town?]
On Wed, 20 May 2009 14:04:36 +0100, Radomir Cernoch radomir.cern...@gmail.com wrote: MP píše v St 20. 05. 2009 v 14:16 +0200: I wonder, can we have at some place (wiki?) some definition file that will specify these per-country default limits in some machine-readable way? Yes, surely! My personal idea of best solution is to use the Semantic wiki, because it provides both machine-readable and human-readable format in one place. Agreed. This sounds like a very good idea. It's even planned to shift OSM from MediaWiki to Semantic Wiki as soon as the wiki will be running on a more powerful hardware (I hope this information is not outdated). Radomír Černoch ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] [Fwd: Re: zones for motorway/in town/outof town?]
On Wed, May 20, 2009 at 2:26 PM, marcus.wolsc...@googlemail.com wrote:
On Wed, 20 May 2009 14:04:36 +0100, Radomir Cernoch
radomir.cern...@gmail.com wrote:
MP píše v St 20. 05. 2009 v 14:16 +0200:
I wonder, can we have at some place (wiki?) some definition file that
will specify these per-country default limits in some machine-readable
way?
Yes, surely! My personal idea of best solution is to use the Semantic
wiki, because it provides both machine-readable and human-readable
format in one place.
Agreed. This sounds like a very good idea.
I think it sounds like a terrible idea.
A) We have a geo-database for geographic information
B) We have a wiki for project-support information
Why would this particular geo-data not live in the Geodatabase?
Let's take the very first bit of the example:
country(cz) {
How can I tell if a particular way is in the country cz? Maybe I
need a lookup table that gives me a list of coordinates to specificy
the boundary of that country. Should this be in the wiki too? Do we
have somewhere better for storing lists of coordinates?
So let's make the assumption we have an object (I'm guessing a
relation would be handy) for each country explaining where it is. Now
if only there was a way of assigning attributes to the country to hold
information that applied to that country. Geez, maybe we could allow
tags on relations?
Hmmm. Or maybe we should ditch the whole geo-db idea and just put
everything into a wonderful Semantic Wiki.
Cheers,
Andy
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Re: [OSM-talk] [Fwd: Re: zones for motorway/in town/outof town?]
Hi,
if only I knew that the idea would arouse so intense emotions! Ok, now I
know that I should be more careful with the word semantic next time.
Andy Allan píše v St 20. 05. 2009 v 14:48 +0100:
On Wed, May 20, 2009 at 2:26 PM, marcus.wolsc...@googlemail.com wrote:
On Wed, 20 May 2009 14:04:36 +0100, Radomir Cernoch
radomir.cern...@gmail.com wrote:
MP píše v St 20. 05. 2009 v 14:16 +0200:
I wonder, can we have at some place (wiki?) some definition file that
will specify these per-country default limits in some machine-readable
way?
Yes, surely! My personal idea of best solution is to use the Semantic
wiki, because it provides both machine-readable and human-readable
format in one place.
Agreed. This sounds like a very good idea.
I think it sounds like a terrible idea.
A) We have a geo-database for geographic information
B) We have a wiki for project-support information
Why would this particular geo-data not live in the Geodatabase?
Let's take the very first bit of the example:
country(cz) {
How can I tell if a particular way is in the country cz? Maybe I
need a lookup table that gives me a list of coordinates to specificy
the boundary of that country. Should this be in the wiki too? Do we
have somewhere better for storing lists of coordinates?
Of course not.
So let's make the assumption we have an object (I'm guessing a
relation would be handy) for each country explaining where it is. Now
if only there was a way of assigning attributes to the country to hold
information that applied to that country. Geez, maybe we could allow
tags on relations?
I do not mind putting all this into the relations for each country.
However the question is, how complicated the whole system will be.
If we end up with 'speed_city', 'speed_rural' and 'speed_highway', then
why not. However there is a danger of ending up with tags like:
'speed_limit_on_highway_inside_polygon_tagged_place' or
'speed_limit_on_primary_not_in_any_polygon_tagged_place_or_built-up'.
This is an old problem of relational-database expressiveness. For now I
propose to wait until we collect all nitty-gritties of all different
traffic regulations we know. The discussion about implementation can
come second.
Hmmm. Or maybe we should ditch the whole geo-db idea and just put
everything into a wonderful Semantic Wiki.
When someone invents indexes into ontology, which would be as fast as
indexes into geo-db, why not? Personally I am rather sceptical about it.
;-)
Cheers,
Andy
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Re: [OSM-talk] [Fwd: Re: zones for motorway/in town/outof town?]
On Wed, May 20, 2009 at 3:22 PM, Radomir Cernoch radomir.cern...@gmail.com wrote: Hi, if only I knew that the idea would arouse so intense emotions! Ok, now I know that I should be more careful with the word semantic next time. Heh. It's mainly that I have a reflexive preference for geo-databases whenever I see the concept of spatial-intersection tests. And a dislike for putting machine-readable code into the wiki, semantic or not. I do not mind putting all this into the relations for each country. However the question is, how complicated the whole system will be. Don't over-plan for edge cases! Make the simple things simple and the complicated things possible. Cheers, Andy ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] [Fwd: Re: zones for motorway/in town/outof town?]
Am Wednesday 20 May 2009 schrieb Andy Allan:
On Wed, May 20, 2009 at 2:26 PM, marcus.wolsc...@googlemail.com wrote:
On Wed, 20 May 2009 14:04:36 +0100, Radomir Cernoch
radomir.cern...@gmail.com wrote:
MP píše v St 20. 05. 2009 v 14:16 +0200:
I wonder, can we have at some place (wiki?) some definition file that
will specify these per-country default limits in some machine-readable
way?
Yes, surely! My personal idea of best solution is to use the Semantic
wiki, because it provides both machine-readable and human-readable
format in one place.
Agreed. This sounds like a very good idea.
I think it sounds like a terrible idea.
A) We have a geo-database for geographic information
B) We have a wiki for project-support information
Why would this particular geo-data not live in the Geodatabase?
Let's take the very first bit of the example:
country(cz) {
How can I tell if a particular way is in the country cz? Maybe I
need a lookup table that gives me a list of coordinates to specificy
the boundary of that country. Should this be in the wiki too? Do we
have somewhere better for storing lists of coordinates?
one way would be, to check if the way is inside the cz-polygon.
the other way, which I think fits more into the osm style would be an
inclusion of the country.
for an ordinary rural street something like
zone:traffic = CZ:out_of_town
for example...
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[OSM-talk] [Fwd: Re: zones for motorway/in town/outof town?]
Guenther Meyer píše v Čt 21. 05. 2009 v 00:49 +0200: Am Wednesday 20 May 2009 schrieb Radomir Cernoch: ...but you would need some kind of gis database/functions to evaluate the polygon data. the easy way of reading just keys and values like with most of the other features in the osm database would not be possible. I have read somewhere (a few weeks ago) that querying whether a point lies in a country can be done quickly. I was assuming that the same should be possible for any polygon. However I am not aware of technical details. Can anyone confirm this, please? Radek Černoch ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
