Roger, thank you very much, I am looking forward to analysing this.
Please note that I only have a standard OSM excerpt of places and no special 1950s dataset. Just in case this has not been made clear in my previous email. Cheers, Christoph "Roger Slevin" <ro...@slevin.plus.com> schrieb: > I'll see whether it is possible to get a file exported which includes > the "inactive" localities and let you know ... there may be some > value in running a comparison between your 1950s data and the more > recent data in NPTG. > > Best wishes > > Roger > > > -----Original Message----- > From: Christoph Böhme [mailto:christ...@b3e.net] > Sent: 29 July 2009 18:36 > To: ro...@slevin.plus.com > Cc: 'Public transport/transit/shared taxi related topics'; 'Peter > Miller' Subject: Re: [Talk-transit] Naptan import > > "Roger Slevin" <ro...@slevin.plus.com> schrieb: > > > Christoph > > > > Sorry - I now realise I shouldn't have referred to "inactive" > > localities ... this is something I can see on the editor system for > > NPTG, but the export only shows the active localities ... the > > records of the inactive ones are not included in the standard XML > > file. I would need to check whether it is possible to get an > > extract from NPTG which includes inactive records (or only > > comprises the inactive ones) - but that is a question I will only > > ask if someone can suggest that some useful purpose could be served > > by having access to that data. > > The only reason for using the inactive data I can see is a comparison > with OSM-only places. This could indicate NPTG places which might have > been deactivated because they are not part of the public transport > network. Unless we want to add data from NPTG to existing OSM stops > (e.g. the locality code) this information is probably more relevant to > the DoT than OSM. > > However, since places in OSM might be derived from NPE maps, OSM-only > places could also mean that the locality has been abandoned in the > time since 1950. Your brief history of NPTG indicates to me that the > data is probably much more recent then NPE's 1950 data. It might > therefore be interesting to know which places are only in OSM and not > even in the inactive NPTG data. Such places have then probably been > abandoned a long time ago. > > Christoph > > > Roger > > > > -----Original Message----- > > From: Christoph Böhme [mailto:christ...@b3e.net] > > Sent: 28 July 2009 22:54 > > To: ro...@slevin.plus.com; Public transport/transit/shared taxi > > related topics > > Cc: ro...@slevin.plus.com; 'Peter Miller' > > Subject: Re: [Talk-transit] Naptan import > > > > Roger, > > > > thank you for your explanations. > > > > "Roger Slevin" <ro...@slevin.plus.com> schrieb: > > > > > Although NPTG was originally for public transport purposes, we > > > stressed at all times that a locality should be listed even if it > > > has no public transport - but we know that some local editors have > > > probably erred towards marking some unserved rural hamlets as > > > "inactive". > > > > > > All "inactive" localities should still be in the data - so hamlets > > > which are missing may be in NPTG, but marked as "inactive". > > > > What would an inactive entry look like in the data? The xml schema > > does not seem to define any elements/attributes for inactive > > entries. > > > > > However they may simply never have been in the source data - and > > > no one to date has recognised the need to add them to NPTG. It > > > would be interesting to see what localities OSM holds in its data > > > which are not included in NPTG (as well as the reverse of this) > > > if that is possible. > > > > I created two tables of OSM- and NTPG-only places: > > > > http://www.mappa-mercia.org/nptg/nptg-only-localities.csv.gz > > http://www.mappa-mercia.org/nptg/osm-only-localities.csv.gz > > > > I considered a place to be only in one dataset if no place from the > > other dataset exists in its proximity which has the same name. > > Proximity was defined as an euclidian distance less than 0.3 between > > the lat/lon positions of the places (I don't know how this relates > > to kilometres/miles). Since the OSM data contains some nodes with > > place-tags that have nothing with actual places, I only included > > nodes with a place-value of either locality, island, suburb, hamlet, > > village, municipality, town or city. I also excluded place=farm. > > > > Christoph > > > _______________________________________________ Talk-transit mailing list Talk-transit@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-transit
