[Talk-GB] Finding Unmapped public rights of way

[Craig Wallace]

On 2013-07-27 13:11, Dudley Ibbett wrote:
> Hi
>
> I'm trying to make use of the row files on rowmaps for derbyshire and
> staffordshire and and merging these with and osm map file to then
> produce maps that can highlight which paths are and aren't mapped.  I
> can put the derbyshire file into JOSM and download parts of the area and
> merge them to create an osm file that I can then save locally and import
> into Maperative.  A modified rules file allows me to produce the prow
> footpath ways and the osm footpath ways as different coloured dotted
> lines so I can see which are/aren't mapped.  Unfortunately JOSM doesn't
> seem to be able to cope with merging large files.  I maybe asking to
> much of it as the files are quite big.  What I would like is to be able
> to get a merged file of the derbyshire, saffordshire row files and the
> equivalent osm map file on a regular basis (highlighting the rows that
> aren't mapped) so I can slowly pick away at the remaining footpaths the
> need mapping in this area.  Does anyone know of a simple way to do this?

Depends on how big the files are, and how much memory you have on your 
computer. You can assign more memory to JOSM, which might help. eg run 
it with a command like this:
java -Xmx1500M -jar josm-tested.jar
That would allow it 1500MB.


Or for merging large files, you could use Osmosis. 
http://wiki.openstreetmap.org/wiki/Osmosis
ie use a command like this:
osmosis --rx file2.osm --rx file1.osm --m --wx merged.osm

Craig