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.
Shri -----Original Message----- From: "Ghosh, Swarnava" <[email protected]<mailto:[email protected]>> Date: Tue, 16 Sep 2014 14:10:56 -0400 To: <[email protected]<mailto:[email protected]>> Subject: [petsc-users] General query, default preconditioner Hello, 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. Specifically, I am using the following lines of code: KSPCreate(PETSC_COMM_WORLD,&pOfdft->ksp); KSPSetType(pOfdft->ksp, KSPGMRES); KSPSetOperators(pOfdft->ksp,A,A,SAME_NONZERO_PATTERN); KSPSetTolerances(pOfdft->ksp,KSPTOL,PETSC_DEFAULT,PETSC_DEFAULT,PETSC_DEFAULT); KSPSetFromOptions(pOfdft->ksp); KSPSetUp(pOfdft->ksp); Regards, Swarnava --
