[OSM-talk] A forest ... what?

Martin Koppenhoefer dieterdreist at gmail.com
Mon Apr 10 10:27:11 UTC 2017


2017-04-10 12:16 GMT+02:00 Warin <61sundowner at gmail.com>:

> In JOSM there is a tool to simplify ways with errors of less than 3 metres
> in order to reduce the data base size.
> This amount of error is judged acceptable.
>


you can use the algorithm with any acceptable error margin set, but please
not on _other_ people's work. It will lead to problems for the angles (e.g.
sharp turns) and generally only regards distances and not angles. The
algorithm doesn't know about crossing ways which still have to be mapped
(and which may make currently superfluous nodes still reasonably placed).
The 3m default in JOSM (or is it less) does not mean it is generally
accepted to simplify ways with this setting and re-upload them. If you do a
good manual drawing, you won't improve anything by applying douglas peucker
to the result (the algorithm used in "simplify ways"), all you will do is
introduce problems, maybe tiny and in few occassions, but still problems.

Cheers,
Martin
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