[OSM-talk] Potlatch & duplicated node

[Peter Miller]

> Date: Wed, 27 Aug 2008 17:59:37 +0100
> From: "David Groom" <reviews at pacific-rim.net>
> Subject: [OSM-talk] Potlatch & duplicated node
> To: <talk at openstreetmap.org>
> Message-ID: <013101c90866$4ad41830$6401a8c0 at xp1>
> Content-Type: text/plain; format=flowed; charset="iso-8859-1";
> 	reply-type=original
> 
> Whilst reviewing data I've noted recently a large number of duplicated
> nodes.  These occur where one way joins another.
> 
> I've managed to create a few myself, but have noted that many other users
> are doing the same.  In each instance the relevant ways have "created by
> Potlatch" as tags.
> 
> I presume that :
> 
> (1) Either there must be a bug in Potlatch
> (2) Its far too easy for a user to inadvertently create duplicated nodes.
> 
> Take for example the area
> http://www.openstreetmap.org/index.html?mlat=13.166319744096374&mlon=-
> 61.239985647460315&zoom=12
> .  The validator in JOSM reports 176 duplicated nodes.
> 
> Same area  as shown on informationfreeway
> http://www.informationfreeway.org/?lat=13.153544792952308&lon=-
> 61.222993541715226&zoom=15&layers=0000T0B0F
> 
> I would stress I'm not blaming the users who created the data in that
> area.
> I count myself as a fairly experienced OSM mapper, and as I stated earlier
> I
> have been managing to create some duplicated nodes, and that's even after
> reading and re-reading the Potlatch editing FAQ.
> 
> If its not a bug in Potlatch, then could the program be changed so that it
> is much harder to duplicate nodes.
>
Also, when manipulating ways which are parts of relations it seems to be
possible to break the Potlatch/Server link and end up with duplicate ways. I
think the best way to do this is to split and join and delete ways which is
part of a relation. I haven't worked it through in detail to understand
exactly what is happening and give the repeatable formula but could do if
that was useful if others haven't already done this.

Sometimes I find I have a way which is part of a relationship which refuses
to die. If I remove all the nodes except for two, then remove the
relationship and all the tags then it I seem to be able to delete the last
two.

Finally, a question. If I have a pair of ways on top of each other (the edge
of a park and a road for example that share nodes; is there any way to
select the way I am actually interested in rather than just the one that is
'on top'?



Regards



PeterIto