<div dir="ltr">Dear Jed, <br><br>The following is the result with the options you told
me. The iteration has converged, while converged at a wrong solution,
compared to the result from LU. <br><br>tutorials]$ time ./ex78 -Ain
A_phi -rhs rhs_phi -solu solu_phi -noshift -pc_type hypre
-pc_hypre_type parasails -ksp_gmres_restart 600 -ksp_rtol 1e-7 -ksp_typ
gmres -ksp_monitor_true_residual -ksp_converged_reason<div class="im"><br>
<br> Read matrix in ascii format ...<br>m: 288399, n: 288399, nz: 4023176 <br> read A completed <br> rowNumber[0] = 13 <br> rowNumber[1] = 13 <br> rowNumber[2] = 19 <br> read A is complete ! <br><br> Read rhs in ascii format ...<br>
<br> Read exact solution in ascii format ...<br></div> 0 KSP preconditioned resid norm 1.311815748108e+00 true resid norm 3.838432566849e-03 ||r(i)||/||b|| 1.000000000000e+00<br> 1 KSP preconditioned resid norm 5.507600629359e-01 true resid norm 1.878066463331e-03 ||r(i)||/||b|| 4.892795250727e-01<br>
2 KSP preconditioned resid norm 4.013507277599e-01 true resid norm 1.785692106749e-03 ||r(i)||/||b|| 4.652138797934e-01<br> 3 KSP preconditioned resid norm 3.186589484171e-01 true resid norm 1.939928539000e-03 ||r(i)||/||b|| 5.053960191341e-01<br>
4 KSP preconditioned resid norm 2.533816267053e-01 true resid norm 2.182716525094e-03 ||r(i)||/||b|| 5.686478756839e-01<br> 5 KSP preconditioned resid norm 1.956749847727e-01 true resid norm 2.436511231157e-03 ||r(i)||/||b|| 6.347672360328e-01<br>
6 KSP preconditioned resid norm 1.489551919079e-01 true resid norm 2.625495747280e-03 ||r(i)||/||b|| 6.840020507214e-01<br> 7 KSP preconditioned resid norm 1.129706022530e-01 true resid norm 2.726727688051e-03 ||r(i)||/||b|| 7.103753004809e-01<br>
8 KSP preconditioned resid norm 8.528153693722e-02 true resid norm 2.764872691683e-03 ||r(i)||/||b|| 7.203129515839e-01<br> 9 KSP preconditioned resid norm 6.419522418091e-02 true resid norm 2.765551151077e-03 ||r(i)||/||b|| 7.204897058665e-01<br>
10 KSP preconditioned resid norm 4.793073337207e-02 true resid norm 2.754803244091e-03 ||r(i)||/||b|| 7.176896288040e-01<br> 11 KSP preconditioned resid norm 3.590594904610e-02 true resid norm 2.738481920714e-03 ||r(i)||/||b|| 7.134375485361e-01<br>
12 KSP preconditioned resid norm 2.683482240096e-02 true resid norm 2.722031760807e-03 ||r(i)||/||b|| 7.091519033880e-01<br> 13 KSP preconditioned resid norm 2.001207136261e-02 true resid norm 2.709429246945e-03 ||r(i)||/||b|| 7.058686585627e-01<br>
14 KSP preconditioned resid norm 1.493908729876e-02 true resid norm 2.699791991674e-03 ||r(i)||/||b|| 7.033579318265e-01<br> 15 KSP preconditioned resid norm 1.111558666088e-02 true resid norm 2.692890954089e-03 ||r(i)||/||b|| 7.015600527536e-01<br>
16 KSP preconditioned resid norm 8.272119255509e-03 true resid norm 2.688069519102e-03 ||r(i)||/||b|| 7.003039580057e-01<br> 17 KSP preconditioned resid norm 6.143976425601e-03 true resid norm 2.684895702336e-03 ||r(i)||/||b|| 6.994771057136e-01<br>
18 KSP preconditioned resid norm 4.563685459707e-03 true resid norm 2.682859292253e-03 ||r(i)||/||b|| 6.989465740324e-01<br> 19 KSP preconditioned resid norm 3.394656398417e-03 true resid norm 2.681459888330e-03 ||r(i)||/||b|| 6.985819971124e-01<br>
20 KSP preconditioned resid norm 2.518916365228e-03 true resid norm 2.680609739005e-03 ||r(i)||/||b|| 6.983605136526e-01<br> 21 KSP preconditioned resid norm 1.872307188353e-03 true resid norm 2.680081243394e-03 ||r(i)||/||b|| 6.982228283859e-01<br>
22 KSP preconditioned resid norm 1.390334828536e-03 true resid norm 2.679742748684e-03 ||r(i)||/||b|| 6.981346427259e-01<br> 23 KSP preconditioned resid norm 1.034606694934e-03 true resid norm 2.679535108562e-03 ||r(i)||/||b|| 6.980805476966e-01<br>
24 KSP preconditioned resid norm 7.710134967260e-04 true resid norm 2.679397134577e-03 ||r(i)||/||b|| 6.980446022989e-01<br> 25 KSP preconditioned resid norm 5.725407938260e-04 true resid norm 2.679329449922e-03 ||r(i)||/||b|| 6.980269688889e-01<br>
26 KSP preconditioned resid norm 4.272990427118e-04 true resid norm 2.679284171589e-03 ||r(i)||/||b|| 6.980151728414e-01<br> 27 KSP preconditioned resid norm 3.181341598383e-04 true resid norm 2.679247206576e-03 ||r(i)||/||b|| 6.980055426050e-01<br>
28 KSP preconditioned resid norm 2.368729933003e-04 true resid norm 2.679233163958e-03 ||r(i)||/||b|| 6.980018841799e-01<br> 29 KSP preconditioned resid norm 1.766017339700e-04 true resid norm 2.679224053276e-03 ||r(i)||/||b|| 6.979995106376e-01<br>
30 KSP preconditioned resid norm 1.313377419946e-04 true resid norm 2.679217016981e-03 ||r(i)||/||b|| 6.979976775210e-01<br> 31 KSP preconditioned resid norm 9.789603459870e-05 true resid norm 2.679213290696e-03 ||r(i)||/||b|| 6.979967067380e-01<br>
32 KSP preconditioned resid norm 7.275708495896e-05 true resid norm 2.679210423371e-03 ||r(i)||/||b|| 6.979959597340e-01<br> 33 KSP preconditioned resid norm 5.412802491776e-05 true resid norm 2.679209810847e-03 ||r(i)||/||b|| 6.979958001573e-01<br>
34 KSP preconditioned resid norm 4.026672785271e-05 true resid norm 2.679209362635e-03 ||r(i)||/||b|| 6.979956833876e-01<br> 35 KSP preconditioned resid norm 2.990907253308e-05 true resid norm 2.679208426592e-03 ||r(i)||/||b|| 6.979954395269e-01<br>
36 KSP preconditioned resid norm 2.226822676398e-05 true resid norm 2.679208136434e-03 ||r(i)||/||b|| 6.979953639342e-01<br> 37 KSP preconditioned resid norm 1.654703590780e-05 true resid norm 2.679208182746e-03 ||r(i)||/||b|| 6.979953759996e-01<br>
38 KSP preconditioned resid norm 1.229268254949e-05 true resid norm 2.679208209944e-03 ||r(i)||/||b|| 6.979953830852e-01<br> 39 KSP preconditioned resid norm 9.149145951039e-06 true resid norm 2.679208050822e-03 ||r(i)||/||b|| 6.979953416303e-01<br>
40 KSP preconditioned resid norm 6.813825018110e-06 true resid norm 2.679207932900e-03 ||r(i)||/||b|| 6.979953109089e-01<br> 41 KSP preconditioned resid norm 5.075333494970e-06 true resid norm 2.679208029175e-03 ||r(i)||/||b|| 6.979953359907e-01<br>
42 KSP preconditioned resid norm 3.770609781438e-06 true resid norm 2.679208069198e-03 ||r(i)||/||b|| 6.979953464175e-01<br> 43 KSP preconditioned resid norm 2.808924777973e-06 true resid norm 2.679208000517e-03 ||r(i)||/||b|| 6.979953285246e-01<br>
44 KSP preconditioned resid norm 2.094599249993e-06 true resid norm 2.679207985642e-03 ||r(i)||/||b|| 6.979953246492e-01<br> 45 KSP preconditioned resid norm 1.559223301396e-06 true resid norm 2.679208018840e-03 ||r(i)||/||b|| 6.979953332981e-01<br>
46 KSP preconditioned resid norm 1.160309778657e-06 true resid norm 2.679208029228e-03 ||r(i)||/||b|| 6.979953360044e-01<br> 47 KSP preconditioned resid norm 8.638154916854e-07 true resid norm 2.679208013013e-03 ||r(i)||/||b|| 6.979953317800e-01<br>
48 KSP preconditioned resid norm 6.436084879799e-07 true resid norm 2.679208008459e-03 ||r(i)||/||b|| 6.979953305937e-01<br> 49 KSP preconditioned resid norm 4.797395939888e-07 true resid norm 2.679208018385e-03 ||r(i)||/||b|| 6.979953331796e-01<br>
50 KSP preconditioned resid norm 3.573839482305e-07 true resid norm 2.679208020910e-03 ||r(i)||/||b|| 6.979953338374e-01<br> 51 KSP preconditioned resid norm 2.662426448119e-07 true resid norm 2.679208017655e-03 ||r(i)||/||b|| 6.979953329896e-01<br>
52 KSP preconditioned resid norm 1.984893339085e-07 true resid norm 2.679208016597e-03 ||r(i)||/||b|| 6.979953327137e-01<br> 53 KSP preconditioned resid norm 1.484050273141e-07 true resid norm 2.679208018006e-03 ||r(i)||/||b|| 6.979953330809e-01<br>
54 KSP preconditioned resid norm 1.106994152625e-07 true resid norm 2.679208019541e-03 ||r(i)||/||b|| 6.979953334807e-01<br>Linear solve converged due to CONVERGED_RTOL iterations 54<br><br> Accuracy of the soltuion on the solution from LU: | u -U_lu |_2 : 3321.15 <br>
<br> Iteration number is : 54 <br><br> Accuracy of the soltuion: | b - A*u |_2 : 0.004681 <br><br>real 0m15.393s<br>user 0m14.895s<br>sys 0m0.251s<br><br><br><div class="gmail_quote"><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
<br>
Message: 2<br>
Date: Thu, 10 Nov 2011 14:49:55 -0600<br>
From: Jed Brown <<a href="mailto:jedbrown@mcs.anl.gov">jedbrown@mcs.anl.gov</a>><br>
Subject: Re: [petsc-users] Any suggestion for this kinds of matrix?<br>
To: PETSc users list <<a href="mailto:petsc-users@mcs.anl.gov">petsc-users@mcs.anl.gov</a>><br>
Message-ID:<br>
<CAM9tzSkW7PZaBLH_sXpxToYv6x3seupTQcY+sPj=<a href="mailto:fHc_ax-AjA@mail.gmail.com">fHc_ax-AjA@mail.gmail.com</a>><br>
Content-Type: text/plain; charset="utf-8"<br>
<br>
On Thu, Nov 10, 2011 at 14:45, Bao Kai <<a href="mailto:paeanball@gmail.com">paeanball@gmail.com</a>> wrote:<br>
<br>
> PCFIELDSPLIT seems a little more complex, I will try that.<br>
><br>
> I tried some different preconditioners, only lu can get right results.<br>
><br>
> With some pc, some wrong results can be obtained, such as the following<br>
> one.<br>
><br>
> tutorials]$ time ./ex78 -Ain A_in -rhs rhs -solu solu -noshift -pc_type<br>
> hypre -pc_hypre_type parasails -ksp_gmres_restart 600 -ksp_rtol 1e-5<br>
> -ksp_typ gmres<br>
><br>
<br>
Always run with -ksp_monitor_true_residual -ksp_converged_reason when<br>
checking whether a preconditioner is working.<br>
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