[OSM-talk] Duplicate data nodes/segments/ways

[Frederik Ramm]

Hi,

 > I've just run into a problem with duplicate data on an area I'm 
working on.
 > I just noticed when I tried to move a node in JOSM which revealed a way
 > including nodes an segments underneath those that were moved. I'm 
guessing
 > that maybe this has come about following a failed upload from within 
JOSM,
 > it's happened once or twice when the connection to the server as 
dropped. My
 > question is... Is there any way to easily find this duplicate information
 > and preferably clean it up too? By easily I mean without having to 
manually
 > go through an OSM dump or try moving hundreds nodes to see if anything
 > appears underneath them in JOSM...

Download the area in question, and run maplint on it (see 
http://wiki.openstreetmap.org/index.php/Maplint). This will light up 
problems like duplicate nodes or ways.

Then manually correct the problems in JOSM. There is one cool feature in 
JOSM which I haven'T fully understood yet. If you select, using the 
rectangle selection tool, a number of nodes/segments that are part of a 
way, and then hit the delete button, JOSM will *not* delete the selected 
items, but only those that are duplicates. (Try for yourself, create 
three nodes at the same spot, connect one node to something else, 
rectangle-select them, click delete - only the unconnected ones are 
deleted.) It is probably not really meant to be a feature but a side 
effect, but it works pretty well for such situations. If, however, your 
selection contains a full way with all its nodes and segments, 
everything is deleted. (Use Undo then.)

I know you had hoped for something easier but that's the best I can come 
up with.

Bye
Frederik

-- 
Frederik Ramm  ##  eMail frederik at remote.org  ##  N49°00.09' E008°23.33'