[OSM-talk] extracts for historical views at a specific point in time
Paul Norman
penorman at mac.com
Thu Aug 14 22:21:32 UTC 2014
On 8/14/2014 6:59 AM, Richard Welty wrote:
> i have a need to be able to generate mapnik tiles for
> part of NY State to show what the OSM view of it
> looked like maybe 2 years ago. is there a documented
> process for pulling an extract like that?
Two years ago is before the redaction, so you need CC BY-SA data.
The easy way is to get the closest date from
http://planet.openstreetmap.org/cc-by-sa/ and import it with current
tools and the current style. You could also use the XML style as of that
date.
If you want a date between planet files, you'll have to download one and
update it with daily diffs.
If you're doing this for many dates, you may find it easier to extract
from the planet dump with history, but for just one or two dates, what I
describe is an easier method than manipulating that giant file.
Remember, most of the history is recent and the planet from then is
about 60% of the current planet size.
If you're dealing with data prior to version 0.6 of the API, you may
need to downgrade osmosis to extract data from the files. For version
0.4 and earlier, you'll need to use other tools to handle the data model
changes. Of course, for data that old, you probably don't need to
extract as the full planet is under 1GB.
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