GMRES: Convergence
billy at dem.uminho.pt
billy at dem.uminho.pt
Sun Nov 19 16:47:31 CST 2006
I have specified maximum number of iterations 500 and tolerance 1E-8. Usually it
drives the residual to specified tolerance but in this case GMRES seems to stop
after 15 iterations and the residual is still above tolerance.
0 KSP Residual norm 2.928143483788e+05
1 KSP Residual norm 1.403875955158e+05
2 KSP Residual norm 4.068852804332e+04
3 KSP Residual norm 8.517044011269e+03
4 KSP Residual norm 2.179034005404e+03
5 KSP Residual norm 6.155723927227e+02
6 KSP Residual norm 1.636241232571e+02
7 KSP Residual norm 4.839052750735e+01
8 KSP Residual norm 1.118719384434e+01
9 KSP Residual norm 3.313977141518e+00
10 KSP Residual norm 7.447603108045e-01
11 KSP Residual norm 1.942386237492e-01
12 KSP Residual norm 4.843647894709e-02
13 KSP Residual norm 1.215264193249e-02
14 KSP Residual norm 3.111716140560e-03
15 KSP Residual norm 7.922640853896e-04
Matrix p Number of iterations: 15 Residual: +7.922641E-04
Anyone knows why this happens?
Billy.
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