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Good afternoon. I am a student at the Faculty of Mathematics and for my course work I need to solve SLAE with a relative accuracy of 1e-8 or more. To do this, I created the function PetscCall(KSPSetTolerances(ksp, 1. e-8, PETSC_DEFAULT, PETSC_DEFAULT,
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<div><div>Good afternoon. I am a student at the Faculty of Mathematics and for my course work I need to solve SLAE with a relative accuracy of 1e-8 or more. To do this, I created the function PetscCall(KSPSetTolerances(ksp, 1.e-8, PETSC_DEFAULT, PETSC_DEFAULT, 100000));. But in the end, only 38 iterations were made and the relative norm ||Ax-b||/||b|| it turns out 4.54011. If you reply to my email, I can give you more information about the solver settings.</div></div>