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Hi,
ah, ok that's it, we are using these 3 options: -eps_error_absolute -eps_error_relative -eps_error_backward The first two gives the warning but the last one gives no warning but the values... Thanks a lot! :) Eric On 2024-03-07 10:36, Jose E. Roman wrote: > You are calling EPSErrorView() somehow. This function checks the residual errors. If you requested EPS_ERROR_RELATIVE then the error for the zero eigenvalues will be large (division by 0). > Are you calling EPSErrorView() three times? Probably the 3rd message is a call with EPS_ERROR_ABSOLUTE, in which case all errors are below the tolerance. > > Jose > > >> El 7 mar 2024, a las 16:29, Eric Chamberland <[email protected]> escribió: >> >> Hi, >> wow, it was only that, it's now working perfectly! >> Curiously, I still have 2 times the message about relative errors followed by a new one with converged values, see: >> options_eps_gen Linear eigensolve converged (13 eigenpairs) due to CONVERGED_TOL; iterations 2 >> Problem: some of the first 10 relative errors are higher than the tolerance >> >> Problem: some of the first 10 relative errors are higher than the tolerance >> >> All requested eigenvalues computed up to the required tolerance: >> 0.00000, 0.00000, 0.00000, 199.28609, 415.65289, 570.21994, 1294.72406, 1295.67360, >> 3769.78800, 3771.15894 >> >> >> So is it intended to write these 2 warnings? >> Anyway thanks a lot! :) >> Eric >> >> On 2024-03-07 02:24, Jose E. Roman wrote: >>> Pierre's diagnostic is right, but the suggested option is wrong: it should be -eps_target >>> Also, I would suggest using a larger value, such as -eps_target 0.1, otherwise the tolerance 1e-14 might not be attained. >>> >>> Jose >>> >>> >>> >>>> El 7 mar 2024, a las 8:01, Pierre Jolivet <[email protected]> escribió: >>>> >>>> This Message Is From an External Sender >>>> This message came from outside your organization. >>>> It seems your A is rank-deficient. >>>> If you slightly regularize the GEVP, e.g., -st_target 1.0E-6, you’ll get errors closer to 0. >>>> >>>> Thanks, >>>> Pierre >>>> >>>> >>>>> On 6 Mar 2024, at 8:57 PM, Eric Chamberland via petsc-users <[email protected]> wrote: >>>>> >>>>> This Message Is From an External Sender >>>>> This message came from outside your organization. >>>>> Hi, >>>>> >>>>> we have a simple generalized Hermitian problem (Kirchhoff plate >>>>> vibration) for which we are comparing SLEPc results with Matlab results. >>>>> >>>>> SLEPc computes eigenvalues correctly, as Matlab does. >>>>> >>>>> However, the output eigenvectors are not fully converged and we are >>>>> trying to understand where we have missed a convergence parameter or >>>>> anything else about eigenvectors. >>>>> >>>>> SLEPc warns us at the end of EPSSolve with this message: >>>>> >>>>> --- >>>>> Problem: some of the first 10 relative errors are higher than the >>>>> tolerance >>>>> --- >>>>> >>>>> And in fact, when we import the resulting vectors into Matlab, >>>>> "A*x-B*Lambda*x" isn't close to 0. >>>>> >>>>> Here are attached the EPS view output as the A and B matrices used. >>>>> >>>>> Any help or insights will be appreciated! :) >>>>> >>>>> Thanks, >>>>> Eric >>>>> >>>>> <epsview.txt><matrice0_gen.m><matrice1_gen.m> >>>>> >> -- >> Eric Chamberland, ing., M. Ing >> Professionnel de recherche >> GIREF/Université Laval >> (418) 656-2131 poste 41 22 42 -- Eric Chamberland, ing., M. Ing Professionnel de recherche GIREF/Université Laval (418) 656-2131 poste 41 22 42
