[OSM-dev] Extracting Great Britain and Ireland from planet.osm

[Keith Sharp]

Hello,

Following on from last weeks discussion about reducing the size of the
planet.osm data set for particular use cases I have modified a script
written by Frederik Ramm that extracted data for Germany so that it
extracts data for Great Britain, Ireland, the Channel Islands, the Isles
of Scilly, St Kilda, Orkney, and Shetland.  The polygon I used can be
seen:

	http://www.passback.co.uk/maps/gbirl.html

You can download the script from:

	http://www.passback.co.uk/maps/extract-gb-irl.pl

You run the script as follows:

	./extract-gb-irl.pl < planet-070307.osm > gb-irl.osm

On my system a run took just over 5 minutes wall clock time, I have not
looked at memory usage in any detail, but it looked about 50MB max
resident size in top (not the best measure, I know).  The uncompressed
file is reduced from 3.40Gb to 0.22Gb, bzip2 compressed size is 16Mb.

I have done a little checking of the data and it looks like it is
working as expected, but I would appreciate if others could check as
well.  Would it be possible to get the script added to the OSM SVN,
preferably next to Frederiks script.

A final question, I created the visualisation of the polygon in Google
Maps because I could not see how to do the same thing using the OSM
infrastructure, am I correct in thinking that there is no public API for
OSM at this stage?

Thanks,

Keith.