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Hi There, We have a matrix that is singular and trying to solve it. We first use an iterative solve with KSPBCGS, the solution vector is nan values and the converged reason from PETSc of KSP_DIVERGED_NANORINF, that's great and what I would
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<div dir="ltr">Hi There,<div><br></div><div>We have a matrix that is singular and trying to solve it. We first use an iterative solve with KSPBCGS, the solution vector is nan values and the converged reason from PETSc of KSP_DIVERGED_NANORINF, that's great and what I would expect.</div><div><br></div><div>Sometimes in our program we redo a failed solve using the MKL Pardiso solver, when the same matrix and vectors get put into that solver which is a KSPPREONLY, I get KSP_CONVERGED_ITS as a converged reason and solution vector with nan values in it. </div><div><br></div><div>Stepping through the PETSc calls, I see that the external call to Pardiso doesn't return an error for this, so not really the fault of PETSc, but curious if y'all have seen this before or a solution/workaround to this?<br clear="all"><div><div dir="ltr" class="gmail_signature" data-smartmail="gmail_signature"><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><b><br></b></div><div dir="ltr"><b>Chris Hewson</b><div>Senior Reservoir Simulation Engineer</div><div>ResFrac</div><div>+1.587.575.9792</div></div></div></div></div></div></div></div></div></div>