Am 21.06.19 um 21:27 schrieb Ken Mankoff:
On 2019-06-21 at 21:10 +02, Robert Nuske <[email protected]> wrote...
If there is no way to only treat the islands/holes (which i don't know
about), it will change the outer boundary as well. Fjord like
structures will vanish. Neighboring areas might even merge if close
enough. And since one can not control the buffer style of sharp edges
(like in postgis, geos), everything will become "rounder".
Can you work in raster space or do you have to remain with resolution-agnostic
vectors? I've solved this issue with maintaining coastlines in raster space by
finding and saving the largest (or several largest) clumps (e.g. the ocean
surrounding my domain), filling all holes which may involve filling the sea or
growing the coastline, and then re-applying the saved clumps, thereby removing
any artificially rounded coast.
r.clump input=raster output=clumps
clump_ID_largest=$(r.stats -c clumps sort=desc | head -n1 | cut -d" " -f1)
r.mapcalc "mask_ocean = if(clumps == ${clump_ID_largest}, null(), 1)"
r.mfilter -z input=raster output=raster_overfilled filter=filter.txt
r.mapcalc "raster_filled = raster_overfilled * mask_ocean" --o
-k.
Interesting idea. Using the ocean like a stencil. Will think about it.
Could work similarly in vector world.
Will have to test first if Markus Metz is right and v.clean rmarea does
what I want. Maybe i haven't studied carefully enough my tests.
Thanks Ken
regards
robert
robert
_______________________________________________
grass-user mailing list
[email protected]
https://lists.osgeo.org/mailman/listinfo/grass-user
