<html>
<head>
<meta content="text/html; charset=windows-1252"
http-equiv="Content-Type">
</head>
<body bgcolor="#FFFFFF" text="#000000">
<div class="moz-cite-prefix">On 12/20/13 3:40 PM, Que Cat wrote:<br>
</div>
<blockquote
cite="mid:CA+Z2Wfi38CtJ-nKSfSBHGqe=6Qn3yN9RAe5h59gY1kHE8c=S8A@mail.gmail.com"
type="cite">
<meta http-equiv="Content-Type" content="text/html;
charset=windows-1252">
<div dir="ltr"><font face="times new roman, serif">Barry,</font>
<div><font face="times new roman, serif"><br>
</font></div>
<div><font face="times new roman, serif">It said that "No
support for this operation for this object type! Matrix
format mpiaij does not have a built-in PETSc LU!".</font></div>
</div>
</blockquote>
Try with -pc_factor_mat_solver_package mumps (superlu_dist)<br>
<br>
If you didn't install them reconfigure with:<br>
<br>
--download-scalapack=1<br>
--download-mumps=1<br>
<br>
or:<br>
<br>
--download-superlu_dist=1<br>
<br>
Or just run sequentially<br>
<br>
Anton<br>
<blockquote
cite="mid:CA+Z2Wfi38CtJ-nKSfSBHGqe=6Qn3yN9RAe5h59gY1kHE8c=S8A@mail.gmail.com"
type="cite">
<div dir="ltr">
<div><font face="times new roman, serif"><br>
</font></div>
<div><font face="times new roman, serif">I run it with optio<span
style="background-color:rgb(255,255,255)">n "<code
style="color:rgb(0,0,0)">-snes_monitor
-ksp_monitor_true_residual -snes_converged_reason
-ksp_converged_reason</code><span
style="color:rgb(0,0,0)">." and received : </span></span></font></div>
<div><span
style="color:rgb(0,0,0);background-color:rgb(213,234,255)"><font
face="times new roman, serif">
<div> 0 SNES Function norm 1.414213647226e-01 </div>
<div> 0 KSP preconditioned resid norm
8.424084241999e+08 true resid norm 1.414213647226e-01
||r(i)||/||b|| 1.000000000000e+00</div>
<div> 1 KSP preconditioned resid norm
1.354908290122e-02 true resid norm 1.424694873074e-01
||r(i)||/||b|| 1.007411345428e+00</div>
<div>Nonlinear solve did not converge due to
DIVERGED_LINE_SEARCH iterations 0</div>
<div>
<br>
</div>
<div>It looks like that the preconditioned residual
converges, but the true residual does not.</div>
</font></span></div>
</div>
<div class="gmail_extra"><br>
<br>
<div class="gmail_quote">On Fri, Dec 20, 2013 at 8:30 AM, Barry
Smith <span dir="ltr"><<a moz-do-not-send="true"
href="mailto:bsmith@mcs.anl.gov" target="_blank">bsmith@mcs.anl.gov</a>></span>
wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0
.8ex;border-left:1px #ccc solid;padding-left:1ex"><br>
Run with<br>
<br>
-snes_mf_operator -pc_type lu<br>
<br>
I’m sorry I sent the wrong instructions before.<br>
<span class="HOEnZb"><font color="#888888"><br>
Barry<br>
</font></span>
<div class="HOEnZb">
<div class="h5"><br>
On Dec 20, 2013, at 7:54 AM, Que Cat <<a
moz-do-not-send="true"
href="mailto:quecat001@gmail.com">quecat001@gmail.com</a>>
wrote:<br>
<br>
> Hi Barry,<br>
><br>
> Thanks for your exlanation. I used -snes_mf
-pc_type lu and now it failed with reason -3 (/* the
linear solve failed */). So, something is wrong with the
function.<br>
><br>
><br>
> On Thu, Dec 19, 2013 at 5:01 PM, Barry Smith <<a
moz-do-not-send="true"
href="mailto:bsmith@mcs.anl.gov">bsmith@mcs.anl.gov</a>>
wrote:<br>
><br>
> ratio is || A - Afd || /||A|| where |||| is the
frobenus norm and difference is || A - Afd ||.<br>
><br>
> Try using -snes_mf -pc_type lu<br>
><br>
> This can often converge even if the A you
provide is wrong, so if this convergence sine then
likely the Jacobian is wrong.<br>
><br>
> It is also possible that the function evaluation
has a bug.<br>
><br>
> <a moz-do-not-send="true"
href="http://www.mcs.anl.gov/petsc/documentation/faq.html#newton"
target="_blank">http://www.mcs.anl.gov/petsc/documentation/faq.html#newton</a><br>
><br>
><br>
> Barry<br>
><br>
><br>
><br>
> On Dec 19, 2013, at 4:26 PM, Que Cat <<a
moz-do-not-send="true"
href="mailto:quecat001@gmail.com">quecat001@gmail.com</a>>
wrote:<br>
><br>
> > Hello,<br>
> ><br>
> > I use SNES to solve the non linear coupled
equations. I have checked the hand-coded jacobian with
-snes_type test and received the result:<br>
> > Norm of matrix ratio 1.39606e-23 difference
1.53372e-14 (user-defined state)<br>
> > Norm of matrix ratio 3.03157e-10 difference
0.33305 (constant state -1.0)<br>
> > Norm of matrix ratio 3.03157e-10 difference
0.33305 (constant state 1.0)<br>
> > It said that " if the ratio is O(1.e-8), the
hand-coded Jacobian is probably correct." What is the
second paramenter "difference 1.53372e-14 ...."? Does it
play any role in checking the accuracy of hand-coded
jacobian?<br>
> ><br>
> > The SNES solver for failed with the reason -6
"the line search failed". I tried with all other line
search method stated in the PETSC manual, but they all
failed.<br>
> ><br>
> > I tried to figure out what is wrong with my
code? Could you please give me any recommendation to
direct me how to check my code? I appreciate your help.<br>
> ><br>
> > QUe<br>
> ><br>
><br>
><br>
<br>
</div>
</div>
</blockquote>
</div>
<br>
</div>
</blockquote>
<br>
</body>
</html>