I've been struggling for days with a problem concerning my Taylor-Hood-Navier-Stokes-system. The PARDISO solver refuses to solve my symmetric Stokes-system correctly (upper triangular), but if I use the non-symmetric version of PARDISO (and use the full matrix, of course), it works. In the latter case, the solution is comparable to UMFPACK and Matlab and MINRES.
Altought you may think "what's the problem? you're going NAVIER-Stokes (and non-symmetric matrices) anyway!", but I need the non-convective linear Stokes-case as well.
Attached you find the "symm"-files (upper triangular matrix, one-based, coordinate format and vectors uu and ff) and the "non-symm"-files (one-based, coordinate format and the vectors). I double-checked it with matlab, the matrices are identical (nonsymm = symm + transpose(symm) - diag(symm)) and the right-hand-sides ff are identical, too.
- Ubuntu 12.04.1 LTS (GNU/Linux 3.2.0-36-generic x86_64)
- Model: 6.44.2 "Intel(R) Xeon(R) CPU E5640 @ 2.67GHz"
- same problem on some Core i7.
Maybe it is just a problem of the matrices condition... but I'm wondering why this never has been an issue in my problems before. Maybe I missed something else...
Thank you very much!