2010/8/18, Markus Neteler <[email protected]>: > On Wed, Aug 18, 2010 at 8:31 AM, Hanlie Pretorius > <[email protected]> wrote: >> Hi, >> >> I'm posting here because I had no reaction on the users email list. > > > (Hint: if you post an example for a sampe data set like Spearfish or > North Carolina, then it is way easier to reproduce for us...) > >> I'm using GRASS64 RC6 on Linux 10.04 (64-bit) and I'm trying to run >> r.sim.water on a catchment about 5000 km2 in size. >> >> I started with a very fine resolution in my region (00:00:00.18) and >> got the following: >> ----- >> GRASS 6.4.0RC6 (world_wgs84):~ > r.sim.water >> elevin=lieb_dem_25m_clipped dxin=lieb_dem_25m_clipped_dx >> dyin=lieb_dem_25m_clipped_dy rain_val=2.0 manin_val=0.1 >> infil_val=13.0 depth=rsimwater.depth.18s disch=rsimwater.disch.18s >> default nwalk=600505650, rwalk=600505650.000000 >> Killed > > Here for NC: > > g.region -d res=1000 -p > r.slope.aspect elevation=elevation dx=elevation_dx dy=elevation_dy > r.sim.water elevin=elevation dxin=elevation_dx dyin=elevation_dy \ > rain_val=2.0 manin_val=0.1 infil_val=13.0 \ > depth=rsimwater.depth.18s disch=rsimwater.disch.18s > ... > WARNING: Infiltration exceeds the rainfall rate everywhere! No overland > flow. > ... > Number of iterations = 0 cells > Time step = 129663.85 s > GRASS 6.4.0svn (nc_spm_08):~ > > > So no crash. But my region had way less pixels. > >> ---- >> >> Since this resolution gives about 300 million cells in the region, I >> progressively coarsened the resolution, but I get buffer overflows >> even with just 2736 cells in the region (resolution = 00:01:00) > > The question is; how big are the internal tmp files? > Did you compile GRASS with large file support (--enable-largefile)? >
I did not compile GRASS myself - have not tried that before - so I just used the version as the Ubuntu package manager installed it. I will try to find out how to compile GRASS and then use to options to enable large file support and the debugging symbols. >> Below is an example of the error I got at a resolution of 1 minute. >> The output at all resolutions (except 00:00:00.18) is similar: > > Second possibility is a bug when having LatLong coordinates. I > used a metric system. > > ... >> Time step = 0.00 s >> *** buffer overflow detected ***: r.sim.water terminated >> ======= Backtrace: ========= > > We would need a full backtrace (maybe not posted to the list) > which requires GRASS compiled with debugging symbols. > >> I can run the Spearfish example as shown in the r.sim.water manual >> page and that region contains 2654802 cells. > > Could you prepare a LatLong example with public data? I will get the Spearfish dataset into a LatLong location and see what happens when I run r.sim.water on that. I could place the Spearfish latlong location on a temporary web site if needed. > >> My DEM is not rectangular and I'm setting the region to a vector file >> that is an irregular boundary. So, the DEM has NULL values outside the >> vector boundary but inside the region. Could this be a problem? > > I don't think so. > > Markus > Thanks for the help. _______________________________________________ grass-dev mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/grass-dev
