[OHM] hudson river waterway

[SK53]

I think it's worth adjusting the 'centre' line. I haven't got to the point
with my experiments
<http://sk53-osm.blogspot.co.uk/2016/10/skeletons-in-water.html> with
straight skeletons & approximate medial lines to be comfortable that there
is a relatively easy way to derive decent centre-lines. At least for know
my problems are of two types:


   - Even with the PostGIS AML function one ends up with a multilinestring
   with lots of dangles. So one option is to recursively prune the structure.
   - An alternative way to find a path through the AML (or Straight
   Skeleton) is to route through it. I've done some little experiments with
   pg_routing which work fine, but havent thought about how such things scale.

If I've missed some well-known algorithms for these purposes do let me know.

Jerry

On 27 March 2017 at 00:30, Richard Welty <rwelty at averillpark.net> wrote:

> been editing a bunch in the area around Albany & Troy New York.
> there's a linear waterway feature which is supposed to represent
> the Hudson River, in addition to the polygons that somewhat accurately
> represent the river. the waterway feature isn't terribly accurate, in fact
> it's rather ugly looking on the map. here is one location where you
> see the straight line off to the left of the semi-accurate polygons:
>
>   http://www.openhistoricalmap.org/go/ZdrHMUa~--?layers=H
>
> so what value is it bringing? delete or adjust to the rough
> centerline of the river?
>
> richard
>
> --
> rwelty at averillpark.net
>  Averill Park Networking - GIS & IT Consulting
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