Re: [OSM-talk] osmxapi/bbox question
Hi, Currently i'm working with the bbox of Belgium, but this bbox includes parts of the Netherlands, France,.. And this gives me some problems... it appears that some places in Belgium also exists in the Netherlands or France. Apparently it is only possible to use bbox-es to limit the size. Are there any ideas or plans to implement some way you can limit the size for eg. a country? Johan 80n wrote: You can have any shaped bbox you like as long as it is a rectangle ;) Can anyone point me to a good algorithm for selecting points within an arbitrary polygon? 80n On Fri, Apr 11, 2008 at 1:01 PM, Johan Huysmans [EMAIL PROTECTED] mailto:[EMAIL PROTECTED] wrote: Hi All, I' experimenting with osmxapi to get a list of all places in Belgium. Getting a list of all places is no problem, but the list is a bit too large ;) Can I specify that I only want the places in Belgium? Can this be done with bbox? Is there a known mapping that give you the exact bbox for each country? Thx, Johan Huysmans ___ talk mailing list talk@openstreetmap.org mailto:talk@openstreetmap.org http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk
Re: [OSM-talk] osmxapi/bbox question
Download from here, it uses a polygon instead of a bbox. http://download.geofabrik.de/osm/europe/ On Fri, Apr 18, 2008 at 10:04 AM, Johan Huysmans [EMAIL PROTECTED] wrote: Hi, Currently i'm working with the bbox of Belgium, but this bbox includes parts of the Netherlands, France,.. And this gives me some problems... it appears that some places in Belgium also exists in the Netherlands or France. Apparently it is only possible to use bbox-es to limit the size. Are there any ideas or plans to implement some way you can limit the size for eg. a country? Johan 80n wrote: You can have any shaped bbox you like as long as it is a rectangle ;) Can anyone point me to a good algorithm for selecting points within an arbitrary polygon? 80n On Fri, Apr 11, 2008 at 1:01 PM, Johan Huysmans [EMAIL PROTECTED] mailto:[EMAIL PROTECTED] wrote: Hi All, I' experimenting with osmxapi to get a list of all places in Belgium. Getting a list of all places is no problem, but the list is a bit too large ;) Can I specify that I only want the places in Belgium? Can this be done with bbox? Is there a known mapping that give you the exact bbox for each country? Thx, Johan Huysmans ___ talk mailing list talk@openstreetmap.org mailto:talk@openstreetmap.org http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk
Re: [OSM-talk] osmxapi/bbox question
i would be cool if the osmxapi could accept a href to a polygon xml file reference instead of a bbox. We can put a list of country/province/city/... polygons somewhere on a site 2008/4/18, Johan Huysmans [EMAIL PROTECTED]: And a combination of both? Does that exists. Now my php script just eats all memory when parsing the osm file :( Johan Skywave wrote: Download from here, it uses a polygon instead of a bbox. http://download.geofabrik.de/osm/europe/ On Fri, Apr 18, 2008 at 10:04 AM, Johan Huysmans [EMAIL PROTECTED] wrote: Hi, Currently i'm working with the bbox of Belgium, but this bbox includes parts of the Netherlands, France,.. And this gives me some problems... it appears that some places in Belgium also exists in the Netherlands or France. Apparently it is only possible to use bbox-es to limit the size. Are there any ideas or plans to implement some way you can limit the size for eg. a country? Johan 80n wrote: You can have any shaped bbox you like as long as it is a rectangle ;) Can anyone point me to a good algorithm for selecting points within an arbitrary polygon? 80n On Fri, Apr 11, 2008 at 1:01 PM, Johan Huysmans [EMAIL PROTECTED] mailto:[EMAIL PROTECTED] wrote: Hi All, I' experimenting with osmxapi to get a list of all places in Belgium. Getting a list of all places is no problem, but the list is a bit too large ;) Can I specify that I only want the places in Belgium? Can this be done with bbox? Is there a known mapping that give you the exact bbox for each country? Thx, Johan Huysmans ___ talk mailing list talk@openstreetmap.org mailto:talk@openstreetmap.org http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk
Re: [OSM-talk] osmxapi/bbox question
That's exactly what i mean/want :D That way you can call the osmxapi url with [polygon=belgium] or [polygon:country=belgium] What do the osmxapi developers think about it? Greetings Johan Rob wrote: i would be cool if the osmxapi could accept a href to a polygon xml file reference instead of a bbox. We can put a list of country/province/city/... polygons somewhere on a site 2008/4/18, Johan Huysmans [EMAIL PROTECTED]: And a combination of both? Does that exists. Now my php script just eats all memory when parsing the osm file :( Johan Skywave wrote: Download from here, it uses a polygon instead of a bbox. http://download.geofabrik.de/osm/europe/ On Fri, Apr 18, 2008 at 10:04 AM, Johan Huysmans [EMAIL PROTECTED] wrote: Hi, Currently i'm working with the bbox of Belgium, but this bbox includes parts of the Netherlands, France,.. And this gives me some problems... it appears that some places in Belgium also exists in the Netherlands or France. Apparently it is only possible to use bbox-es to limit the size. Are there any ideas or plans to implement some way you can limit the size for eg. a country? Johan 80n wrote: You can have any shaped bbox you like as long as it is a rectangle ;) Can anyone point me to a good algorithm for selecting points within an arbitrary polygon? 80n On Fri, Apr 11, 2008 at 1:01 PM, Johan Huysmans [EMAIL PROTECTED] mailto:[EMAIL PROTECTED] wrote: Hi All, I' experimenting with osmxapi to get a list of all places in Belgium. Getting a list of all places is no problem, but the list is a bit too large ;) Can I specify that I only want the places in Belgium? Can this be done with bbox? Is there a known mapping that give you the exact bbox for each country? Thx, Johan Huysmans ___ talk mailing list talk@openstreetmap.org mailto:talk@openstreetmap.org http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk
Re: [OSM-talk] osmxapi/bbox question
On Fri, Apr 18, 2008 at 3:14 PM, Johan Huysmans [EMAIL PROTECTED] wrote: That's exactly what i mean/want :D That way you can call the osmxapi url with [polygon=belgium] or [polygon:country=belgium] What do the osmxapi developers think about it? It's a nice idea. I just need to implement the algorithm described earlier in this thread :) 80n Greetings Johan Rob wrote: i would be cool if the osmxapi could accept a href to a polygon xml file reference instead of a bbox. We can put a list of country/province/city/... polygons somewhere on a site 2008/4/18, Johan Huysmans [EMAIL PROTECTED]: And a combination of both? Does that exists. Now my php script just eats all memory when parsing the osm file :( Johan Skywave wrote: Download from here, it uses a polygon instead of a bbox. http://download.geofabrik.de/osm/europe/ On Fri, Apr 18, 2008 at 10:04 AM, Johan Huysmans [EMAIL PROTECTED] wrote: Hi, Currently i'm working with the bbox of Belgium, but this bbox includes parts of the Netherlands, France,.. And this gives me some problems... it appears that some places in Belgium also exists in the Netherlands or France. Apparently it is only possible to use bbox-es to limit the size. Are there any ideas or plans to implement some way you can limit the size for eg. a country? Johan 80n wrote: You can have any shaped bbox you like as long as it is a rectangle ;) Can anyone point me to a good algorithm for selecting points within an arbitrary polygon? 80n On Fri, Apr 11, 2008 at 1:01 PM, Johan Huysmans [EMAIL PROTECTED] mailto:[EMAIL PROTECTED] wrote: Hi All, I' experimenting with osmxapi to get a list of all places in Belgium. Getting a list of all places is no problem, but the list is a bit too large ;) Can I specify that I only want the places in Belgium? Can this be done with bbox? Is there a known mapping that give you the exact bbox for each country? Thx, Johan Huysmans ___ talk mailing list talk@openstreetmap.org mailto:talk@openstreetmap.org http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk
Re: [OSM-talk] osmxapi/bbox question
Hi, That way you can call the osmxapi url with [polygon=belgium] or [polygon:country=belgium] What do the osmxapi developers think about it? It's a nice idea. I just need to implement the algorithm described earlier in this thread :) Not only do you need to implement the algorithm, you also need a computing environment that will be able to execute the algorithm in an acceptable timeframe. A halfway correct border polygon of a landlocked state easily runs into five-digit numbers of polygon nodes, and then for each of the 250 million nodes in the database, you have to find out whether it lies in that polygon. (An obvious optimization is to compute the largest rectangle contained in, and the largest rectangle containing, the polygon. First check if point is outside the outer bbox - if yes, you're done. Then check if point is inside the inner bbox - if yes, you're done. Only after that do the actual polygon test.) Bye Frederik ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk
Re: [OSM-talk] osmxapi/bbox question
On Fri, Apr 18, 2008 at 4:56 PM, Frederik Ramm [EMAIL PROTECTED] wrote: (An obvious optimization is to compute the largest rectangle contained in, and the largest rectangle containing, the polygon. First check if point is outside the outer bbox - if yes, you're done. Then check if point is inside the inner bbox - if yes, you're done. Only after that do the actual polygon test.) PostGIS is thataway -- :-) Cheers, Andy ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk
Re: [OSM-talk] osmxapi/bbox question
On Fri, Apr 18, 2008 at 4:56 PM, Frederik Ramm [EMAIL PROTECTED] wrote: Hi, That way you can call the osmxapi url with [polygon=belgium] or [polygon:country=belgium] What do the osmxapi developers think about it? It's a nice idea. I just need to implement the algorithm described earlier in this thread :) Not only do you need to implement the algorithm, you also need a computing environment that will be able to execute the algorithm in an acceptable timeframe. A halfway correct border polygon of a landlocked state easily runs into five-digit numbers of polygon nodes, and then for each of the 250 million nodes in the database, you have to find out whether it lies in that polygon. (An obvious optimization is to compute the largest rectangle contained in, and the largest rectangle containing, the polygon. First check if point is outside the outer bbox - if yes, you're done. Then check if point is inside the inner bbox - if yes, you're done. Only after that do the actual polygon test.) Yes, the algorithm is simple, it's implementation is a little more challenging. Bye Frederik ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk
Re: [OSM-talk] osmxapi/bbox question
Karl Newman wrote: On Fri, Apr 11, 2008 at 5:47 AM, 80n [EMAIL PROTECTED] mailto:[EMAIL PROTECTED] wrote: You can have any shaped bbox you like as long as it is a rectangle ;) Can anyone point me to a good algorithm for selecting points within an arbitrary polygon? 80n I don't have it in pseudocode, but one I've heard of casts a ray (horizontal is common) out from the point being tested and then checks the intersection of that ray against each segment of the polygon. If the total number of intersections is odd, then the point lies inside the polygon. If the number is even, then it's outside. This works for holes in a polygon, too. Karl http://en.wikipedia.org/wiki/Point_in_polygon Igor -- http://igorbrejc.net ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk
Re: [OSM-talk] osmxapi/bbox question
On Fri, Apr 11, 2008 at 5:47 AM, 80n [EMAIL PROTECTED] wrote: You can have any shaped bbox you like as long as it is a rectangle ;) Can anyone point me to a good algorithm for selecting points within an arbitrary polygon? 80n I don't have it in pseudocode, but one I've heard of casts a ray (horizontal is common) out from the point being tested and then checks the intersection of that ray against each segment of the polygon. If the total number of intersections is odd, then the point lies inside the polygon. If the number is even, then it's outside. This works for holes in a polygon, too. Karl ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk
