yes and no. One could calculate a polygon with a given maximum of points, but the original extract
from geofabrik contains nodes that lie outside of the bounding polygon.
This is because they try to keep ways complete, and some ways are very, very long.
> Date: Thu, 17 Jan 2013 15:42:11 +0000
> From: zeb@zebulon.org.uk
> To: mkgmap-dev@lists.mkgmap.org.uk
> Subject: Re: [mkgmap-dev] Map size increase using osmupdate vs download
>
> Hi Gerd,
>
> I see what you mean: would it be possible to "rebuild" a poly file
> from an osm file?
>
> Eric
>
> 2013/1/17 Gerd Petermann <gpetermann_muenchen@hotmail.com>:
> > Hi Eric,
> >
> > yes, I think so. You may contact Markus Weber,the author of osmupdate and
> > osmconvert:
> > markus.weber@gmx.com
> > Maybe he can change osmupdate so that it uses the bounding box of the
> > original file
> > to clip the data by default.
> >
> > Ciao,
> > Gerd
> >
> >> Date: Thu, 17 Jan 2013 15:24:59 +0000
> >
> >> From: zeb@zebulon.org.uk
> >> To: mkgmap-dev@lists.mkgmap.org.uk
> >> Subject: Re: [mkgmap-dev] Map size increase using osmupdate vs download
> >>
> >> Hi Gerd,
> >>
> >> Thanks a lot for the -B switch. I read the wiki page about osmupdate,
> >> but did not understand exactly the use of it. Now it is clear! If I
> >> understand well what you are saying, I was merging the GB map with
> >> changes made in the whole world! Am I correct?
> >>
> >> Best,
> >> Eric
> >>
> >> 2013/1/17 Gerd Petermann <gpetermann_muenchen@hotmail.com>:
> >> > Hi Eric,
> >> >
> >> > you have to add
> >> > -B=great_britain.poly
> >> > to your options. See http://download.geofabrik.de/clipbounds/
> >> >
> >> > else osmupdate will add all changes that were made to the whole planet.
> >> > Probably, you also need something like
> >> > --complete-ways --complete-ways
> >> >
> >> > to avoid broken ways in your updated file. These parms are passed to
> >> > osmconvert.
> >> >
> >> > See also http://wiki.openstreetmap.org/wiki/Osmupdate
> >> >
> >> > Ciao,
> >> > Gerd
> >> >
> >> >> Date: Thu, 17 Jan 2013 15:06:50 +0000
> >> >> From: zeb@zebulon.org.uk
> >> >> To: mkgmap-dev@lists.mkgmap.org.uk
> >> >> Subject: Re: [mkgmap-dev] Map size increase using osmupdate vs download
> >> >
> >> >>
> >> >> 2013/1/17 Gerd Petermann <gpetermann_muenchen@hotmail.com>:
> >> >> > Hi Eric,
> >> >> >
> >> >> > what options do you use to update your map? If you download eg.
> >> >> > germany.osm.pbf and later
> >> >> > execute osmupdate.exe without a germany.poly you add all changes of
> >> >> > planet
> >> >> > to your
> >> >> > osm file.
> >> >> >
> >> >> > Does that help?
> >> >> > Gerd
> >> >> >
> >> >>
> >> >> Hi Gerd,
> >> >>
> >> >> Yes, I used:
> >> >> ./osmupdate -v great_britain_previous.o5m great_britain.o5m
> >> >> as well as:
> >> >> ./osmupdate -v great_britain_previous.osm.pbf great_britain.osm.pbf
> >> >>
> >> >> The problem is, if I update a one-day old map (downloaded from
> >> >> Geofabrik), the size of the new, updated map is significantly higher
> >> >> than the same map from Geofabrik the day after. Tomorrow I'll try some
> >> >> tests with today's great britain map to demonstrate this.
> >> >>
> >> >> Eric
> >> >> _______________________________________________
> >> >> mkgmap-dev mailing list
> >> >> mkgmap-dev@lists.mkgmap.org.uk
> >> >> http://lists.mkgmap.org.uk/mailman/listinfo/mkgmap-dev
> >> >
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