Hello everybody, you can now download a first version of the discover-boundaries tool. In its current state, the tool delivers the multipolygons constituting a country's border, in a format suitable to osmosis' --bounding-polygon option. Feel free to ask for a different format it that would fit better.
For the download, please visit http://wmaz.math.uni-wuppertal.de/olbricht/osm/ - the "national boundaries" contains the results and can be accessed via its index.html - the "Discover Boundaries source code" contains the source code. It is described in README and can be used out-of-the-box by the script RUNME and an OSM XML file. I would be grateful for any comments. The biggest issue is at the moment the coastline, for a couple of reasons: * there is way more coastline than any other boundary. For example, in europe the inner-country boundary consists of about 100.000 nodes, but the coastline has about 7 million nodes. So just adding the coastline would make the polygons 70 times more complex. * the coastline doesn't constitute the real border of the country Most countries just don't have their border on the coastline but claim a zone of about 22.2 km (12 nautical miles). See e.g. http://en.wikipedia.org/wiki/Territorial_waters For example, this prevents that a ferry between the mainland and a nearby island already gets an international ferry. So it might be desireable to have as border rather a smoothend 12-nm-zone than the coastline. On the other hand, a typical shape of a country would show exactly the coastline. * the official border is difficult to obtain The "United Nations Convention on the Law of the Sea" leaves it to the respective nations whether they exhaust the full 12-nm-zone or not. But unfortunately, it seems quite difficult to get the data of the official border. I started to try with Germany, but I was not able to find any official document stating the border on the web. The only nation with a complete nautical border in OSM are currently the Netherlands. It should be feasible to derive an automatic 12-nm-zone around any coastline, but this might be quite inaccurate. So what do you think about the options * anyway use the coastline * automatically compute the 12-nm-line and submit it as boundary to OSM * just compute this line inside this tool? The second question is: how do I make the final version of the software a portable and sustainable peace of open source, e.g. how to add a proper make-configure-install script and so on? Cheers, Roland _______________________________________________ dev mailing list [email protected] http://lists.openstreetmap.org/listinfo/dev
