[petsc-users] KSPMonitorSingularValue

[Klaij, Christiaan]

>  You need to run for much more iterations to get any kind of reliable
>singular values. Use something like at least -ksp_gmres_restart 100
>-ksp_max_it 100 and see what happens to the singular values.
>
>    Barry

Barry, Jed,

I followed your advice, this is what happens to the singular values
(taking out some for readability). Do you think these values are
reliable even though the solver doesn't converge? If so what could
be the reason for FGMRES to stagnate?

  0 KSP Residual norm 2.069443859095e-01 % max 1 min 1 max/min 1
  1 KSP Residual norm 2.069442759608e-01 % max 4.08809 min 4.08809 max/min 1
  2 KSP Residual norm 2.069441760813e-01 % max 5.60619 min 4.06952 max/min 1.3776
  3 KSP Residual norm 2.069441732278e-01 % max 9.04702 min 4.0695 max/min 2.22313
  4 KSP Residual norm 2.069440548767e-01 % max 9.39853 min 4.06865 max/min 2.30998
  5 KSP Residual norm 2.069439774947e-01 % max 11.5495 min 4.06865 max/min 2.83866
 10 KSP Residual norm 2.069432503764e-01 % max 14.6194 min 4.04732 max/min 3.61213
 20 KSP Residual norm 2.069424990159e-01 % max 22.7708 min 2.95767 max/min 7.69891
 30 KSP Residual norm 2.069403094003e-01 % max 23.8491 min 2.93612 max/min 8.12265
 50 KSP Residual norm 2.069374104472e-01 % max 24.0821 min 2.23473 max/min 10.7763
 70 KSP Residual norm 2.069306551868e-01 % max 29.3557 min 2.13925 max/min 13.7224
100 KSP Residual norm 2.069163489527e-01 % max 29.4884 min 2.0458 max/min 14.4142


dr. ir. Christiaan Klaij
CFD Researcher
Research & Development
E mailto:C.Klaij at marin.nl
T +31 317 49 33 44

MARIN
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