[GRASS-user] v.surf.rst error: Input window change

[Hamish]

Daniel wrote:
> As an update, if I remove the mask raster option, the interpolation
> finishes ok but it gives me the message at the end...
> 
> G_ludcmp() failed! n=0  d=0.00
> G_ludcmp() failed! n=0  d=0.00
> G_ludcmp() failed! n=0  d=0.00
> v.surf.rst complete.

does the output look ok?
what if you change your region slightly? (e.g. round it outwards to nice
whole numbers with 'g.region -a res=100' followed by resetting back to
your original resolution with 'g.region res=$orig')


If you compiled grass7 with OpenMP support, try 'make distclean' +
recompiling without and see if you still get the error. You might be able
to try the same without recompiling by doing
   export OMP_NUM_THREADS=1
on the command line before v.surf.rst (on the same command line shell).

the specific error messages is from lib/rst/interp_float/matrix.c
+ lib/gmath/lu.c. I guess a matrix with 0 elements counts as 'singular'
and so can't be decomposed. (and so I suspect it is happening before the
OpenMP pragmas are reached, so that could be a red herring)


Hamish