On 12/29/2015 9:41 AM, Dave F. wrote:
I've previously download a file of all OSM data within a rectangular
area. I then use mkgmap to convert it to the format by my Garmin GPSr.
In the future I'd like to change that so it's a multi faceted polygon
of only specified OSM entities.
At present, each time I want to update the file, I'm downloading every
entity, even if they haven't been amended. What I need is to download
any changes within the polygon since I last updated. I read about
minute, hourly & daily diffs. Am I able to state the date I last
updated as the start point for new data?
There appear to be a few programs able to do what I require, but
unsure which is best suited. Is Osmosis a bit overblown for my
purpose. Osmupdate seems a bit more lightweight. Osmconvert appears to
discourage doing what I need:
http://wiki.openstreetmap.org/wiki/Osmupdate#Use_Cases. Overpass also
has a way to download diffs. Anyone used that?
Your best bet is to get an extract from Geofabrik which contains the
areas you need and use their daily diffs to keep it up to date. If you
need a smaller area, extract it from this larger file every day.
Is it better to work with a raw OSM data file or use a .pbf file? In
fact I'm a bit confused what one is. From the wiki it firstly says
"alternative to the XML format", but then goes on to compare it with a
compressed file format. Which is it?
OSM PBFs are raw OSM data, as is OSM XML and o5m. They're just different
file formats. Avoid OSM XML unless you're using software which only
supports that. Use PBF or o5m instead. PBF is easier to use with the
workflow I describe above since you can download a PBF directly from
Geofabrik.
_______________________________________________
dev mailing list
dev@openstreetmap.org
https://lists.openstreetmap.org/listinfo/dev
