<div class="gmail_quote">On Mon, May 16, 2011 at 14:27, Tian(ICT) <span dir="ltr"><<a href="mailto:rongtian@ncic.ac.cn">rongtian@ncic.ac.cn</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">
<font size="2"> 0 KSP preconditioned resid norm 1.393538348796e-001 true
resid norm 7.81673715<br>5471e-001 ||Ae||/||Ax|| 1.000000000000e+000<br> 1
KSP preconditioned resid norm 8.503891307640e-002 true resid norm
9.78452660<br>6728e-001 ||Ae||/||Ax|| 1.251740516806e+000<br> 2 KSP
preconditioned resid norm 2.769264336444e-005 true resid norm
3.06983248<br>7178e+001 ||Ae||/||Ax|| 3.927255613334e+001<br> 3 KSP
preconditioned resid norm 2.140259007162e-005 true resid norm
3.58014377<br>1001e+001 ||Ae||/||Ax|| 4.580099982632e+001<br> 4 KSP
preconditioned resid norm 3.271042954922e-006 true resid norm
3.39507468<br>5413e+000 ||Ae||/||Ax|| 4.343339961273e+000<br> 5 KSP
preconditioned resid norm 8.052808588169e-009 true resid norm
5.12770240<br>1411e-002 ||Ae||/||Ax|| 6.559901272645e-002<br> 29 SNES
Function norm 7.688867566940e-001</font></blockquote></div><br><div>The linear systems are not being solved well. Try</div><div><br></div><div>./pgfem -snes_monitor -snes_mf_operator -mat_mffd_type ds -ksp_type fgmres -ksp_monitor_true_residual -ksp_gmres_modifiedgramschmidt -ksp_rtol 1e-10 -pc_type lu</div>
<div><br></div><div>Remove the -pc_type lu if you have a known null space or otherwise expect the system to be singular.</div>