Hello, I'm trying to turn the English (ceremonial) county boundaries from OSM into MultiPolygons for use with PostGIS. The last step of the process is...
ST_Multi(ST_BuildArea(multi-line string)) ST_BuildArea returns NULL if the given lines do not form a Polygon or MultiPolygon. This has worked fine for the majority of counties, even MultiPolygons like Cumbria and Polygons with holes like Greater London. However, some simple ones such as Kent and County Durham return NULL here and I cannot figure out why. Here's the relation for Kent. http://api.openstreetmap.org/api/0.6/relation/88071/full The relationship analyzer says that the segment for Kent is closed. http://betaplace.emaitie.de/webapps.relation-analyzer/analyze.jsp?relationId=88071 Am I misunderstanding what it means by closed? Looking at the map, it appears to be closed. I have called the PostGIS functions ST_IsRing and ST_IsClosed on the MultiLineString and they return false. Am I making a bad assumption here? I'll be in a lot of trouble if I don't figure this out soon so some help would be greatly appreciated. :) Thanks, James _______________________________________________ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
