Barry Smith schrieb: > Hmm, it sounds like the difference between local "ghosted" vectors > and the global parallel vectors. But I do not understand why any of the > local vector entries would be zero. > Doesn't the vector X that is passed into KSP (or SNES) have the global > entries and uniquely define the solution? Why is viewing that not right? >
I still don't understand fully the underlying processes of the whole PCNN solution procedure, but trying around I substituted MatCreateIS(commw, ind_length, ind_length, PETSC_DECIDE, PETSC_DECIDE, gridmapping, &A); by MatCreateIS(commw, PETSC_DECIDE, PETSC_DECIDE, actdof, actdof, gridmapping, &A); and received the needed results. Furthermore it seems, that the load balance is now better, although I still don't reach the expected values, e.g. ilu-cg 320 iterations, condition 4601 cg only 1662 iterations, condition 84919 nn-cg on 2 nodes 229 iterations, condition 6285 nn-cg on 4 nodes 331 iterations, condition 13312 or is it not to expect, that nn-cg is faster than ilu-cg? cheers, ando -- /"\ Grassl Andreas \ / ASCII Ribbon Campaign Uni Innsbruck Institut f. Mathematik X against HTML email Technikerstr. 13 Zi 709 / \ +43 (0)512 507 6091
