Martin Koppenhoefer kirjoitti: > 2012/10/14 Frederik Ramm <[email protected]>: >> Personally I don't consider the "8" shapes valid - and I don't think >> there's >> a difference between the one with a node in the middle and the one >> without. >> I don't consider the "inner ring touching outer ring in single point" >> case >> to be valid either. > > > IMHO the second case would also be bad mapping if it was technically > valid. There are no such situations in real life and I cannot imagine > a situation where this would not be a bad abstraction.
Hi, The inner triangle could be a cadastral parcel inside another cadastral parcel sharing only one common landmark. For sure such cases exist in real life. Drawing this as one outer ring touching itself in one point seems to be invalid for JTS (self-intersection) while drawing an inner ring touching outer ring at one point is OK for JTS. OpenJUMP is a good tool for testing what JTS thinks about validity. Set Snap to vertises and Prevent edits leading to invalid geometry options on from the settings and start digitizing. -Jukka Rahkonen- > cheers, > Martin > > _______________________________________________ > dev mailing list > [email protected] > http://lists.openstreetmap.org/listinfo/dev > _______________________________________________ dev mailing list [email protected] http://lists.openstreetmap.org/listinfo/dev
