Dear colleagues,
I am using r.gwflow with this sentence:
r.gwflow phead=Npi status=St hc_x=K hc_y=K s=S q=q top=Techo bottom=Muro type=unconfined dt=2592000 output=npf velocity=vel r=rec solver=cg maxit=100000 error=0.0000001 relax=.9 -s --q --o
The initial phead (Npi) is under the top (Techo), but the final phead (npf) overpasses the top of the aquifer in some cells. I guess that is the reason why some warnings appear in the screen, until a last message: WARNING: Matrix is not symmetric!.
WARNING: Matrix unsymmetric: Position [96][86] : [86][96]
Error: -0.023767764282226562 != -0.016727489413544162
difference = 0.007040274868682399
Stop symmetry calculation.
WARNING: Matrix unsymmetric: Position [97][96] : [96][97]
Error: -0.014451045405668651 != -0.016446109008789060
difference = 0.001995063603120410
Stop symmetry calculation.
WARNING: Matrix is not symmetric!
[Raster MASK present]
GRASS 6.4.2svn (ESPPOR):
The program provides an output with the head level. Can we trust that level although the matrix is not symmetric?
Thanks for your help
Luis Barranco