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<div>PETSc defaults to using an ILU(0) preconditioner in serial and Block-Jacobi + ILU(0) on blocks in parallel. You can see the preconditioner details using the option -ksp_view.</div>
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<div>Shri</div>
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<div>-----Original Message-----</div>
<div>From: "Ghosh, Swarnava" <<a href="mailto:sghosh2012@gatech.edu">sghosh2012@gatech.edu</a>></div>
<div>Date: Tue, 16 Sep 2014 14:10:56 -0400</div>
<div>To: <<a href="mailto:petsc-users@mcs.anl.gov">petsc-users@mcs.anl.gov</a>></div>
<div>Subject: [petsc-users] General query, default preconditioner</div>
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<div>Hello,</div>
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<div> I just had a general query if PETSC has something like a "default preconditioner" when preconditioner type is not set and equations are solved using KSPSolve and GMRES method.</div>
<div> Specifically, I am using the following lines of code:</div>
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<div> KSPCreate(PETSC_COMM_WORLD,&pOfdft->ksp); </div>
<div> KSPSetType(pOfdft->ksp, KSPGMRES);</div>
<div> KSPSetOperators(pOfdft->ksp,A,A,SAME_NONZERO_PATTERN);</div>
<div> KSPSetTolerances(pOfdft->ksp,KSPTOL,PETSC_DEFAULT,PETSC_DEFAULT,PETSC_DEFAULT);</div>
<div> KSPSetFromOptions(pOfdft->ksp);</div>
<div> KSPSetUp(pOfdft->ksp); </div>
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<div>Regards,</div>
<div>Swarnava</div>
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<div>-- </div>
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