Yes, but I need to get A, x and b out, so that I can test them in pyamg for other preconditioner options. I can get A, x, and b through what I described, but I do not think x or b is the original one in the linear system.
Is there a simple way to get x and b (I just need once) of TS? Thanks. Qi ________________________________ From: Matthew Knepley <[email protected]> Sent: Thursday, November 10, 2022 6:15 AM To: Tang, Qi <[email protected]> Cc: [email protected] <[email protected]> Subject: Re: [petsc-users] Get solution and rhs in the ts monitor On Thu, Nov 10, 2022 at 3:18 AM Tang, Qi <[email protected]<mailto:[email protected]>> wrote: Hi, How could I get rhs and solution in a ksp solve of ts? I am testing a linear problem (TS_Linear) using a bdf integrator. I tried to get the operator, rhs, and solution in the ts monitor through TSGetKSP and KSPGet***. But r = Ax-b is much larger than the ksp norm. I know the solver works fine. Ax - b is the _unpreconditioned_ norm. By default we are printing the preconditioned norm. You can see the difference by running with -ksp_monitor_true_residual Thanks, Matt Did I misunderstand something about how TS works here? Perhaps one of the vectors is changed after the ksp solve? If so, is there a simple way to get rhs and solution that ksp of ts solved? Thanks, Qi -- What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead. -- Norbert Wiener https://www.cse.buffalo.edu/~knepley/<https://urldefense.com/v3/__http://www.cse.buffalo.edu/*knepley/__;fg!!HXCxUKc!3RV8f9M7XpqGA1c3nvF50ATD6Y_bSM5A5JQIMqg5pWOA-Hq_kiY0qbQKZlYrdS9iU-s0J2cgwCEWJg$>
