On Sun, Nov 26, 2017 at 10:12 PM, Anna Petrášová <[email protected]> wrote: > > On Sun, Nov 26, 2017 at 4:04 PM, Markus Metz > <[email protected]> wrote: > > Hi Vaclav, > > > > On Sun, Nov 26, 2017 at 1:31 AM, Vaclav Petras <[email protected]> wrote: > >> > >> Hi all, > >> > >> r.fill.dir with the bellow artificial DEM leaves part of the directions > >> unresolved and this area is marked in areas, although the area is filled in > >> the output. Here is the code to reproduce: > >> > >> g.region n=220750 s=220000 w=638300 e=639000 nsres=1 ewres=1 rows=750 > >> cols=700 -p > >> r.mapcalc "hills = 500 * sin(row()) + 500 * sin(col())" > >> r.fill.dir input=hills output=filled direction=directions areas=areas > >> > >> In r71809, I have committed a fix which transforms these unresolved > >> directions to NULLs because in the previous implementation (current 7.4svn > >> and older) internal representation of angles was leaking outside of the > >> module. > >> > >> I have 2 questions: > >> > >> Should I backport r71809 to 7.4? > > > > For me, the fix makes sense. > >> > >> Should we pursue this issue further to resolve why these edge cases are > >> not resolved, although they are filled? Does anybody has suggestions at this > >> point? (Paper with the method is linked in the doc.) > > > > I don't think it is worth the pursue the issue of directions any further. > > The module is based on rather old, not to say outdated, methods from the > > 1980's. These methods were developed for DEMs created from contour lines > > which in turn were determined by land surveyors. Back then there was nothing > > like SRTM or LiDAR. > > > > r.hydrodem offers a more advanced method to remove sinks by a combination of > > filling and carving. > > Why don't we move r.hydrodem to core? Is there any reason to keep it in addons?
r.hydrodem needs a testsuite to be moved to core. Markus M > > Anna > > > > > Directions can also be obtained with r.slope.aspect or with the hydrological > > modules r.watershed, r.stream.extract, r.terraflow. Regarding hydrology, > > main flow directions may differ between modules and settings and to > > directions from r.slope.aspect, but all of them are valid according to the > > logic of the underlying algorithm and settings. > > > > Markus M > >> > >> Thank you, > >> Vaclav > >> > >> https://trac.osgeo.org/grass/changeset/71809 > >> https://grass.osgeo.org/grass74/manuals/r.fill.dir.html > >> > >> _______________________________________________ > >> grass-dev mailing list > >> [email protected] > >> https://lists.osgeo.org/mailman/listinfo/grass-dev > > > > > > _______________________________________________ > > grass-dev mailing list > > [email protected] > > https://lists.osgeo.org/mailman/listinfo/grass-dev
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