At 2010-08-19 20:24, Alan Mintz wrote:
I'm mapping in this area:
http://www.openstreetmap.org/?lat=34.08242&lon=-118.639&zoom=17
Along the north side of the tertiary road (whose name is not rendered, but
is Saddle Peak Road) is a state park polygon (Topanga State Park) imported
from CASIL. In this small segment, the road is approximated with less than
70 nodes, while the park polygon segment alongside uses over 1200. I've
noticed similar "beauty" in other data from this source and others (like
the Bakersfield data mentioned recently on the list).
Should imports make an effort to "un-smooth" such data to some extent, for
the benefit of editing and rendering performance, storage, etc?
As a test case, I used JOSM's "Simplify Way" on the ways that make up
Topanga State Park. After playing around a bit, in advanced preferences, I
set simplify-way.max-error to 0.2, which still modeled curves to maybe
single-digit meter errors, yet removed 73% of the nodes (from 9103 to 2466).
The ways are:
38458997
38459009
38459010
38459013
45753168
45753173
45753175
I'm not embarking on a mission to simplify all ways - just taking the
(short time) to do this when I'm mapping an area anyway and see it could be
of benefit.
--
Alan Mintz <alan_mintz+...@earthlink.net>
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