Hi Guiseppe, I've successfully run with 4.5 billion cells. How many cells do you have? I notice you do not have the "-m" flag to tell it to use disk swap in place of all memory. Maybe that would help?
-k. On 2020-05-05 at 11:55 -07, Giuseppe Amatulli <[email protected]> wrote... > Dear GRASS Team > > I am running a global analysis where I need to use "tiles" as computational > units in which I use the following three commands: > r.watershed -b elevation=elv depression=dep accumulation=flow > drainage=dir_rw flow=pixel_area memory=100000 --o --verbose > r.stream.extract elevation=elv accumulation=flow depression=dep > threshold=0.05 direction=dir_rs stream_raster=stream memory=100000 --o > --verbose > r.stream.basins -l stream_rast=stream direction=dir_rs basins=lbasin > memory=100000 --o --verbose > > The basins that were not completely within a tile (resulting in > broken-basins) have been removed (see below the three tiles in Figs. 1,2,3 > including only entire basins), > and now I'm in the phase of merging all the tiles having only complete > basins. > > When I merge the tiles (Fig 4), some basin borders do not match perfectly, > and some areas have NoData (see Fig 5,6) or have the Basin ID of the below > basin (Fig 7). > I noticed that these phenomena appear only when I merge tiles that have > very large broken-basins that can not be included in the tile due to RAM > limitations. > > My thought is that r.stream.basins needs the entire dimension of two > adjacent basins to be able to detect the border without gap and without a > potential random selection. > Is there any part of the r.stream.basins code that I can potentially check > and eventually hack to avoid this problem? > > For the rest, all the RAM limitation and other problem have been solved > soon we will have a global stream network and basin delineation performed > 100% in GRASS!!! > > Thank you > Best Regards > Giuseppe > > > > Fig 1. Left Tile > [image: image.png] > > > Fig 2. Center tile > [image: image.png] > > > Fig 3. Right Tile > [image: image.png] > > > Fig 4. Merge all the tiles > [image: image.png] > > > Fig 5. Gap -> small white area > [image: image.png] > > > Fig 6. Gap -> small white area > [image: image.png] > > Fig 7. boarder Basins inconsistency among tiles > > [image: image.png] _______________________________________________ grass-user mailing list [email protected] https://lists.osgeo.org/mailman/listinfo/grass-user
