I've implemented the algorithmic part of a conflation tool in a JOSM plugin, pretty much following what I wrote down here: http://wiki.openstreetmap.org/wiki/Conflation/Nodes
Right now I'm just using the Euclidean distance in the cost function, but we can of course add other costs like dissimilarity between key values. My big question now is how to present the results to the user, and to allow them to manually confirm/reject matches. All I've done so far is to create a new layer which draws arrows connecting the matched nodes/ways. However that's only a useful visualization tool but doesn't manage the actual conflation process. You can see the option dialog and arrow layer here: http://tinypic.com/r/23sw0u8/7 http://tinypic.com/r/jhd3j7/7 The first question is whether this tool should only merge data from one layer to another, or if it should allow syncing (i.e. bidirectional merging) between layers. The former is of course easier, and can possibly take advantage of existing functionality in JOSM, namely the conflict resolution tools. In fact I've added conflicts which appear in the conflict dialog when the "Conflation" layer is selected. Some things that are missing with that approach is to highlight the arrow connecting the matched nodes, and being able to select the arrow to conflate/resolve the pair of primitives. Also this conflation approach is slightly different from conflict resolution since I'm mostly concerned about resolving tags, and possibly center locations. Right now the conflict tools only support "resolving" conflicts between like primitives, i.e. Node->Node, however I need to allow any combination of Node, Way, or Relation. In other words I may want to match a GNIS feature node (from a fresh GNIS data set) to an existing feature in OSM that may be a node, area, or multipolygon. I'm not so much concerned about the geometry but rather the tags. Conflating geometry is much more complicated and is a future project. :) Any ideas would be much appreciated! -Josh _______________________________________________ josm-dev mailing list josm-dev@openstreetmap.org http://lists.openstreetmap.org/listinfo/josm-dev