On 8/14/20 5:53 PM, yuesu jin wrote:
I also wrote a single thread CG version, which converges well. The
preconditioner in the parallel version is blockJacobi but the single thread
version I used is SSOR. Does it matter to the convergence? Thank you!
Yes, in exactly the ways the error message shows: If you are using a different
preconditioner, you should expect different convergence behavior.
Whether you should expect one or the other method to work (or fail) depends on
the properties of the matrix you are trying to solve. I'd also check whether
the residual 0.00295038 is large or small compared to the initial residual.
What is the tolerance you are using in the SolverControl object?
Best
W.
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Wolfgang Bangerth email: bange...@colostate.edu
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