[petsc-users] KSP_DIVERGED_NAN

[Marco Cisternino]

Hi to everybody,
I wrote an interface elliptic problem solver in 2D and 3D. The linear 
system I assemble depends on the geometrical characteristics of a level 
set function. I tested them with several and more and more complex 
interfaces, but now I would try it with a real 3D interface. But I 
probably have some problem with the computation of a good level set 
function, maybe the cause is the low resolution of the original 
interface. The evidence of my problem is in the subject. No matter what 
iterative petsc solver I try to use the run stops at the first iteration 
with a Nan residual. I don't want to ask you to understand the problem, 
but to give me some information about how to debug I situation like 
this. The interface is too complex to be deeply checked, then I hope 
that looking how the ksp yields a nan residual could help me.
Thank you so much.

Best regards,

     Marco

-- 
Marco Cisternino
PhD Student
Politecnico di Torino
Mobile:+393281189696
Email:marco.cisternino at polito.it