Thanks for your fix Hong. 2016-05-03 17:48 GMT+02:00 Hong <[email protected]>:
> Alejandro : > Fixed > > https://bitbucket.org/petsc/petsc/commits/0043d7fe17a5a8a1e4768ab560023392b3862352 > It will merged to petsc-release after our nightly tests. > > Your detailed report is very helpful, thanks! > > Hong > > Hi, >> >> After updating petsc from version 3.6.2 to 3.7, I had the following >> problem: >> >> The result that I get from doing something like >> MatMult(schurComplement,v1,v2); differs between the petsc versions that I >> mentioned. I traced back the problem to the function >> MatGetSubMatrices_SeqSBAIJ(). What I did in order to temporarily solve my >> problem was to use in petsc 3.7 the code of MatGetSubMatrices_SeqSBAIJ() >> corresponding to petsc 3.6.2. >> >> How I solved the problem is not a real solution, but it allows me to keep >> working. My question is: is it a bug or do you think that there could be >> something wrong with my code from which I use petsc? >> >> I think it should be a bug. If I run the ksp example 59 which uses >> FETI-DP (whose implementation also uses something like >> MatMult(schurComplement,v1,v2)) with petsc 3.7, I get the following >> unexpected answer >> >> mpiexec -n 4 ./ex59 -npx 2 -npy 2 -nex 60 -ney 60 -ksp_max_it 3 >> ------------------FETI-DP stats------------------------------- >> Number of degrees of freedom : 355 >> Number of iterations : 3 >> Eigenvalues preconditioned operator : 1.49e+00 8.86e+00 >> Error betweeen exact and computed solution : 1.91e+00 >> -------------------------------------------------------------- >> >> If I run the same problem with petsc 3.7 but with >> MatGetSubMatrices_SeqSBAIJ() corresponding to petsc 3.6.2, I get the >> expected answer >> >> mpiexec -n 4 ./ex59 -npx 2 -npy 2 -nex 60 -ney 60 -ksp_max_it 3 >> ------------------FETI-DP stats------------------------------- >> Number of degrees of freedom : 355 >> Number of iterations : 3 >> Eigenvalues preconditioned operator : 1.08e+00 2.08e+00 >> Error betweeen exact and computed solution : 3.60e-02 >> -------------------------------------------------------------- >> >> >> Thanks, >> Alejandro >> > >
