On Thu, Aug 28, 2014 at 7:34 AM, Paulo van Breugel <[email protected]> wrote: > On Wed, Aug 27, 2014 at 8:20 PM, Markus Neteler <[email protected]> wrote: >> On Wed, Aug 27, 2014 at 3:25 PM, Paulo van Breugel >> > I forgot to mention that I am using GRASS 7.1 (rev 61757, had it before >> > with rev 61413, but I think I had a similar problem about a year ago). >> > >> > On Wed, Aug 27, 2014 at 10:13 AM, Paulo van Breugel >> >> When running several r.mapcalc in a loop (via R) the function stops >> >> with an error: >> >> >> >> ERROR: Error reading null row 2725 for <MASK> >> >> The error comes from read_null_bits() in >> lib/raster/get_row.c >> >> around >> http://trac.osgeo.org/grass/browser/grass/trunk/lib/raster/get_row.c#L827 >> >> Maybe some off_t definition is missing? > > I don't know what that means; indication of something being wrong with the > data, or in the code?
Question: did you compile with --with-pthread? AFAIK it causes troubles. Markus >> >> The row number varies. This seems to happen at random, and when I >> >> repeat >> >> the same r.mapcalc calculation that stopped with the error before, >> >> things run without problem. >> >> Please tell us also >> - how many raster cells are involved >> - how many files are opened in the loop? > > Last time the error occured in the r.mapcalc below: > > The command: > r.mapcalc --overwrite expression="OUTPUT = if(MESSC==0, 100000* 100.0 * > (MESSB-12300000)/(382900000-12300000), if(MESSC<=5000000, 2*MESSC, > if(MESSC<=10000000, 2*(10000000-MESSC),100000 * 100.0 * (382900000- > MESSB)/(382900000-12300000))))" > produced an error (1) during execution: > ERROR: Error reading null row 2725 for <MASK> > > These layers have 6515140 raster cells, with 3366825 total null cells. The > command is part of a sequence of commands that is run in a loop, but these > are run in sequence so at the time of the error I guess two layers were > open. As I mentioned, running the command again and it will normally run > without problems with the given input layers, and it may go wrong with other > input layers again, without any discernible logic to me. > >> >> >> I tried after removing the mask, and this time no problem so it may >> >> have >> >> to do something with the MASK? (as these error messages only occur once >> >> in a >> >> while, I can't be completely sure it only happens when a MASK is >> >> defined). >> >> >> >> I ran it through R, using the execGRASS() function of the spgrass6 >> >> package. I ran the same, but using the system call instead of >> >> execGRASS. >> >> Still got the same error messages. I therefore guess this has nothing >> >> to do >> >> with R? >> >> Could you "simulate" the loops in a GRASS script outside of R to see >> if it the same? > > > I'll have to figure out how to do that. Perhaps running the r.mapcalc above > several times will do the trick. >> >> >> Markus > > _______________________________________________ grass-dev mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/grass-dev
