On Thu, Jul 5, 2012 at 11:28 AM, Richard Fairhurst <[email protected]> wrote:
> As David said, there isn't, but I'd be happy to look at adding one. That's like a promise of a Christmas present... now I'm all excited! > Assuming that (as ever with Potlatch) we go for a 90% solution rather than > covering every possible combination... am I right in thinking that you'd > like something that combines two areas, with a shared sequence of nodes, > into one? Yup, that sounds about right... > In other words: > A-B-C-D-E-F-G-A > and > H-I-J-C-D-E-K-L-H > become > A-B-C-J-I-H-L-K-E-F-G-A > (and D is deleted) Ooh, muh brayn hertz! That was hard on the old noggin' but, yeah! That's exactly it. The issue with the Canvec data is that it is processed in tiles, and any way that crosses a tile boundary ends up getting chopped up. Linear ways are pretty easy to fix, just select both sections and join them. Areas are a little more work, as they end up with a common border. It usually isn't too hard to combine these sections. You simply need to cut the node at the start of the slice, and delete the common segment, and then do the same for the other segment. Then select each remaining segment and join them. Automating the process would be very nice as it takes a bit to select the right node, cut it, reselect it, make sure you are on the right section of the split way, and then delete the segment, times 2. Selecting both sections of the split area, and having the program find and remove the common border, and then join the two would be super cool! Here's a perfect example, a little pond that is split across a tile boundary... http://www.openstreetmap.org/browse/way/105928394 http://www.openstreetmap.org/browse/way/81343872 Nodes: 1219746948 (also part of ways 81343872 and 81343872) 1219746952 1219746955 1219746957 1219746959 1219746971 1219746974 1219746978 (also part of way 81343872) 1219746948 (also part of ways 81343872 and 81343872) Nodes: 1219746948 (also part of ways 105928394 and 105928394) 1219746978 (also part of way 105928394) 947636778 947636783 947636784 947636785 947636787 947636788 947636789 947636790 947636791 947636792 947636795 1219746948 (also part of ways 105928394 and 105928394) So we can see that nodes 1219746948 and 1219746978 are the two nodes that are shared on that common border. Remove the common ways between those nodes, and merge the remaining sections together. This is about as simple as it gets. There are other situations where relations are cut, or multiple segments need to be merged because the area crosses the boundary multiple times. However, all these situations get broken down into smaller tasks, where in the end, you do end up merging two sections together just as above. There may be more things to do afterwards, but just automating the merge task would be super! -- James VE6SRV _______________________________________________ Talk-ca mailing list [email protected] http://lists.openstreetmap.org/listinfo/talk-ca
