https://community.intel.com/t5/Intel-oneAPI-Math-Kernel-Library/Pardiso-settings-to-better-avoid-errmsg-4/m-p/793826#M2469 Hi Carl,<DIV></DIV><DIV>Thank you for reporting the issue. I will look at it as soon as possible. I'll keep you posted!</DIV><DIV></DIV><DIV>Regards,</DIV><DIV>Konstantin</DIV> Wed, 06 Jul 2011 10:41:17 GMT Konstantin_A_Intel 2011-07-06T10:41:17Z https://community.intel.com/t5/Intel-oneAPI-Math-Kernel-Library/Pardiso-settings-to-better-avoid-errmsg-4/m-p/793825#M2468 Hi,<BR /><BR />I'm using the Pardiso solver in a research code (Fortran90). It has been working quite well, but since I stepped it up a notch recently it has been giving me a few failures of the type "Zero pivot, numerical factorization or iterative refinement problem", i.e. errmsg = -4.<BR /><BR />I previously had some problems with this which was mostly sorted out on this forum in the following thread: <A href="http://software.intel.com/en-us/forums/showthread.php?t=81123&amp;o=a&amp;s=lr">http://software.intel.com/en-us/forums/showthread.php?t=81123&amp;o=a&amp;s=lr</A> But now the problem is back - and it is nasty!<BR /><BR />The problem I wish to solve is a structurally symmetric (real)linear system with a single rhs. However, I use mtype = 11 due to recommendations from Konstantin Arturov in previous thread. I have Lagrange multipliers in my problem so there are a few zeros on the diagonal, whichI store explicitly. The problem size differs, but is on the order of 20k-100k number of equations, where about 0.25%-2.5% of these are Lagrange constraint(multiplier) equations. The resulting number of non-zerosis typically about 1-5 million, so it is not a crazy huge problem, but not in anyway tiny either.<BR /><BR />I suspect that my system matrix may be quite ill-conditioned. (Is there any good way to determine that?) I have been using the solver defaults, i.e.iparm(1) = 0. Since my linear algebra skills are not as sharp as I would like, and my knowledge of sparse matrix methods areclose tonon-existant I was hoping to get some pointers as to what I may try to change in the settings to make this problem go away?<BR /><BR />Best regards,<BR />Carl Wed, 06 Jul 2011 09:14:10 GMT https://community.intel.com/t5/Intel-oneAPI-Math-Kernel-Library/Pardiso-settings-to-better-avoid-errmsg-4/m-p/793825#M2468 dahlberg 2011-07-06T09:14:10Z https://community.intel.com/t5/Intel-oneAPI-Math-Kernel-Library/Pardiso-settings-to-better-avoid-errmsg-4/m-p/793826#M2469 Hi Carl,<DIV></DIV><DIV>Thank you for reporting the issue. I will look at it as soon as possible. I'll keep you posted!</DIV><DIV></DIV><DIV>Regards,</DIV><DIV>Konstantin</DIV> Wed, 06 Jul 2011 10:41:17 GMT https://community.intel.com/t5/Intel-oneAPI-Math-Kernel-Library/Pardiso-settings-to-better-avoid-errmsg-4/m-p/793826#M2469 Konstantin_A_Intel 2011-07-06T10:41:17Z https://community.intel.com/t5/Intel-oneAPI-Math-Kernel-Library/Pardiso-settings-to-better-avoid-errmsg-4/m-p/793827#M2470 Hi Konstantin<BR /><BR />Any news? My problem persists - unfortunately...<BR /><BR />Best regards,<BR />Carl Fri, 15 Jul 2011 18:43:32 GMT https://community.intel.com/t5/Intel-oneAPI-Math-Kernel-Library/Pardiso-settings-to-better-avoid-errmsg-4/m-p/793827#M2470 dahlberg 2011-07-15T18:43:32Z