<div dir="ltr"><div dir="ltr">On Thu, Sep 7, 2023 at 10:18 AM Karthikeyan Chockalingam - STFC UKRI <<a href="mailto:karthikeyan.chockalingam@stfc.ac.uk">karthikeyan.chockalingam@stfc.ac.uk</a>> wrote:<br></div><div class="gmail_quote"><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div class="msg-7912318491967259984">
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<p class="MsoNormal"><span>Yes, I had to zero both the Jacobian and Residual which fixed the SNES convergence problem!
<u></u><u></u></span></p>
<p class="MsoNormal"><span><u></u> <u></u></span></p>
<p class="MsoNormal"><span>This is my first time solving using SNES. From the tutorial<u></u><u></u></span></p>
<p class="MsoNormal"><span><a href="https://petsc4py.readthedocs.io/en/stable/manual/snes/" target="_blank">https://petsc4py.readthedocs.io/en/stable/manual/snes/</a><u></u><u></u></span></p>
<p class="MsoNormal"><span>I didn’t notice the Jacobian and Residual had to be zeroed.</span></p></div></div></div></blockquote><div><br></div><div>Yes, these examples are all FD so the entries are not added to, but set directly. The FEM examples do this zeroing out in the wrapper functions like DMComputeResidualLocal, so it is hard to see.</div><div><br></div><div> Thanks,</div><div><br></div><div> Matt</div><div> </div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div class="msg-7912318491967259984"><div lang="EN-GB" style="overflow-wrap: break-word;"><div class="m_-7912318491967259984WordSection1">
<p class="MsoNormal"><span>Thank you.<u></u><u></u></span></p>
<p class="MsoNormal"><span><u></u> <u></u></span></p>
<p class="MsoNormal"><span>Best,<u></u><u></u></span></p>
<p class="MsoNormal"><span>Karthik.<u></u><u></u></span></p>
<p class="MsoNormal"><span><u></u> <u></u></span></p>
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<p class="MsoNormal" style="margin-bottom:12pt"><b><span style="font-size:12pt;color:black">From:
</span></b><span style="font-size:12pt;color:black">Matthew Knepley <<a href="mailto:knepley@gmail.com" target="_blank">knepley@gmail.com</a>><br>
<b>Date: </b>Thursday, 7 September 2023 at 14:32<br>
<b>To: </b>Chockalingam, Karthikeyan (STFC,DL,HC) <<a href="mailto:karthikeyan.chockalingam@stfc.ac.uk" target="_blank">karthikeyan.chockalingam@stfc.ac.uk</a>><br>
<b>Cc: </b>Stefano Zampini <<a href="mailto:stefano.zampini@gmail.com" target="_blank">stefano.zampini@gmail.com</a>>, <a href="mailto:petsc-users@mcs.anl.gov" target="_blank">petsc-users@mcs.anl.gov</a> <<a href="mailto:petsc-users@mcs.anl.gov" target="_blank">petsc-users@mcs.anl.gov</a>><br>
<b>Subject: </b>Re: [petsc-users] Non-linear solve: DIVERGED_LINE_SEARCH<u></u><u></u></span></p>
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<p class="MsoNormal">On Thu, Sep 7, 2023 at 9:28 AM Karthikeyan Chockalingam - STFC UKRI <<a href="mailto:karthikeyan.chockalingam@stfc.ac.uk" target="_blank">karthikeyan.chockalingam@stfc.ac.uk</a>> wrote:<u></u><u></u></p>
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<p class="MsoNormal">Thank you for your response.<u></u><u></u></p>
<p class="MsoNormal"> <u></u><u></u></p>
<p class="MsoNormal">I will test the Jacobian.<u></u><u></u></p>
<p class="MsoNormal"> <u></u><u></u></p>
<p class="MsoNormal">The linear solve in the second step convergences. Is it possible that Jacobian had been zeroed out?<u></u><u></u></p>
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<p class="MsoNormal"><u></u> <u></u></p>
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<p class="MsoNormal">I think you miss my point. Suppose you did not zero out the Jacobian when you started adding entries. Then you will get something close to twice the value. The linear system will solve fine, but the sep would be wrong.<u></u><u></u></p>
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<p class="MsoNormal"><u></u> <u></u></p>
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<p class="MsoNormal"> Thanks,<u></u><u></u></p>
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<p class="MsoNormal"><u></u> <u></u></p>
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<p class="MsoNormal"> Matt<u></u><u></u></p>
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<p class="MsoNormal"> <u></u><u></u></p>
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<p class="MsoNormal"> <u></u><u></u></p>
<p class="MsoNormal">Best,<u></u><u></u></p>
<p class="MsoNormal">Karthik.<u></u><u></u></p>
<p class="MsoNormal"> <u></u><u></u></p>
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<p class="MsoNormal" style="margin-bottom:12pt"><b><span style="font-size:12pt;color:black">From:
</span></b><span style="font-size:12pt;color:black">Matthew Knepley <<a href="mailto:knepley@gmail.com" target="_blank">knepley@gmail.com</a>><br>
<b>Date: </b>Thursday, 7 September 2</span><span style="font-size:12pt"> ot<span style="color:black">023 at 14:19<br>
<b>To: </b>Chockalingam, Karthikeyan (STFC,DL,HC) <<a href="mailto:karthikeyan.chockalingam@stfc.ac.uk" target="_blank">karthikeyan.chockalingam@stfc.ac.uk</a>><br>
<b>Cc: </b>Stefano Zampini <<a href="mailto:stefano.zampini@gmail.com" target="_blank">stefano.zampini@gmail.com</a>>,
<a href="mailto:petsc-users@mcs.anl.gov" target="_blank">petsc-users@mcs.anl.gov</a> <<a href="mailto:petsc-users@mcs.anl.gov" target="_blank">petsc-users@mcs.anl.gov</a>><br>
<b>Subject: </b>Re: [petsc-users] Non-linear solve: DIVERGED_LINE_SEARCH</span></span><u></u><u></u></p>
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<p class="MsoNormal">On Thu, Sep 7, 2023 at 8:49 AM Karthikeyan Chockalingam - STFC UKRI via petsc-users <<a href="mailto:petsc-users@mcs.anl.gov" target="_blank">petsc-users@mcs.anl.gov</a>> wrote:<u></u><u></u></p>
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<p class="MsoNormal">I just noticed that the line search diverges even for the linear Poisson equation (where the Jacobian is a constant). I am not sure, what I am doing wrong.<u></u><u></u></p>
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<p class="MsoNormal"> <u></u><u></u></p>
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<p class="MsoNormal">You need to test the Jacobian. We have facilities for this. Run using<u></u><u></u></p>
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<p class="MsoNormal"> <u></u><u></u></p>
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<p class="MsoNormal"> --snes_test_jacobian<u></u><u></u></p>
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<p class="MsoNormal"> <u></u><u></u></p>
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<p class="MsoNormal">This will tell you at each step whether the Jacobian matches the finite difference approximant. It looks like your Jacobian at the second step is wrong. Is it possible that you
are not zeroing out the matrix before adding in updates? That would make the second step wrong.<u></u><u></u></p>
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<p class="MsoNormal"> <u></u><u></u></p>
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<p class="MsoNormal"> Thanks,<u></u><u></u></p>
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<p class="MsoNormal"> <u></u><u></u></p>
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<p class="MsoNormal"> Matt<u></u><u></u></p>
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<p class="MsoNormal"> <u></u><u></u></p>
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<p class="MsoNormal"> <u></u><u></u></p>
<p class="MsoNormal">Best,<u></u><u></u></p>
<p class="MsoNormal">Karthik.<u></u><u></u></p>
<p class="MsoNormal"> <u></u><u></u></p>
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<p class="MsoNormal" style="margin-bottom:12pt"><b><span style="font-size:12pt;color:black">From:
</span></b><span style="font-size:12pt;color:black">Chockalingam, Karthikeyan (STFC,DL,HC) <<a href="mailto:karthikeyan.chockalingam@stfc.ac.uk" target="_blank">karthikeyan.chockalingam@stfc.ac.uk</a>><br>
<b>Date: </b>Thursday, 7 September 2023 at 12:19<br>
<b>To: </b>Stefano Zampini <<a href="mailto:stefano.zampini@gmail.com" target="_blank">stefano.zampini@gmail.com</a>><br>
<b>Cc: </b><a href="mailto:petsc-users@mcs.anl.gov" target="_blank">petsc-users@mcs.anl.gov</a> <<a href="mailto:petsc-users@mcs.anl.gov" target="_blank">petsc-users@mcs.anl.gov</a>><br>
<b>Subject: </b>Re: [petsc-users] Non-linear solve: DIVERGED_LINE_SEARCH</span><u></u><u></u></p>
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<p class="MsoNormal">I am trying to solve the non-linear scalar problem<u></u><u></u></p>
<p class="m_-7912318491967259984m-4986576493345623539m6963147566296146480p1">-\nabla \cdot \big( (1+u^2)\nabla u\big)=f<u></u><u></u></p>
<p class="m_-7912318491967259984m-4986576493345623539m6963147566296146480p1">Using finite element formulation.<u></u><u></u></p>
<p class="m_-7912318491967259984m-4986576493345623539m6963147566296146480p1"> <u></u><u></u></p>
<p class="m_-7912318491967259984m-4986576493345623539m6963147566296146480p1">The linear iteration converged – does that mean my Jacobian is correct??<u></u><u></u></p>
<p class="m_-7912318491967259984m-4986576493345623539m6963147566296146480p1"> <u></u><u></u></p>
<p class="m_-7912318491967259984m-4986576493345623539m6963147566296146480p1">I am hoping the non-linear residual goes down to 1-e11.<u></u><u></u></p>
<p class="m_-7912318491967259984m-4986576493345623539m6963147566296146480p1"> <u></u><u></u></p>
<p class="m_-7912318491967259984m-4986576493345623539m6963147566296146480p1">Kind regards,<u></u><u></u></p>
<p class="m_-7912318491967259984m-4986576493345623539m6963147566296146480p1">Karthik.<u></u><u></u></p>
<p class="MsoNormal"> <u></u><u></u></p>
<p class="MsoNormal"> <u></u><u></u></p>
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<p class="MsoNormal" style="margin-bottom:12pt"><b><span style="font-size:12pt;color:black">From:
</span></b><span style="font-size:12pt;color:black">Stefano Zampini <<a href="mailto:stefano.zampini@gmail.com" target="_blank">stefano.zampini@gmail.com</a>><br>
<b>Date: </b>Thursday, 7 September 2023 at 11:49<br>
<b>To: </b>Chockalingam, Karthikeyan (STFC,DL,HC) <<a href="mailto:karthikeyan.chockalingam@stfc.ac.uk" target="_blank">karthikeyan.chockalingam@stfc.ac.uk</a>><br>
<b>Cc: </b><a href="mailto:petsc-users@mcs.anl.gov" target="_blank">petsc-users@mcs.anl.gov</a> <<a href="mailto:petsc-users@mcs.anl.gov" target="_blank">petsc-users@mcs.anl.gov</a>><br>
<b>Subject: </b>Re: [petsc-users] Non-linear solve: DIVERGED_LINE_SEARCH</span><u></u><u></u></p>
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<p class="MsoNormal">The solver did not diverge.<u></u><u></u></p>
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<p class="MsoNormal">It was the line search that was not able to make further progress in minimizing the 2-norm of the residual.<u></u><u></u></p>
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<p class="MsoNormal">This is common in nonlinear solvers. It would help if you tell us what you are trying to solve.<u></u><u></u></p>
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<p class="MsoNormal">Note that at the first step, your residual norm is already 1.e-6. What kind of accuracy do you want?<u></u><u></u></p>
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<p class="MsoNormal"> <u></u><u></u></p>
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<p class="MsoNormal"> <u></u><u></u></p>
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<p class="MsoNormal">Il giorno gio 7 set 2023 alle ore 13:08 Karthikeyan Chockalingam - STFC UKRI via petsc-users <<a href="mailto:petsc-users@mcs.anl.gov" target="_blank">petsc-users@mcs.anl.gov</a>>
ha scritto:<u></u><u></u></p>
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<p class="MsoNormal">Hello,<u></u><u></u></p>
<p class="MsoNormal"> <u></u><u></u></p>
<p class="MsoNormal">The non-linear solution diverged. The final solution seems right and I believe the Jacobian is correct (not 100% certain).
<u></u><u></u></p>
<p class="MsoNormal"> <u></u><u></u></p>
<p class="MsoNormal">I am not sure if I doing something wrong in the solver setting.
<u></u><u></u></p>
<p class="MsoNormal"> <u></u><u></u></p>
<p class="MsoNormal"> <u></u><u></u></p>
<p class="m_-7912318491967259984m-4986576493345623539m6963147566296146480m477101460960849173p1"><span class="m_-7912318491967259984m-4986576493345623539m6963147566296146480m477101460960849173apple-converted-space"><span style="color:black"> </span></span><span style="color:black">0 SNES Function norm
3.890991210938e-03<span class="m_-7912318491967259984m-4986576493345623539m6963147566296146480m477101460960849173apple-converted-space"> </span></span><u></u><u></u></p>
<p class="m_-7912318491967259984m-4986576493345623539m6963147566296146480m477101460960849173p1"><span class="m_-7912318491967259984m-4986576493345623539m6963147566296146480m477101460960849173apple-converted-space"><span style="color:black">
</span></span><span style="color:black">0 KSP Residual norm 9.037762538598e+00<span class="m_-7912318491967259984m-4986576493345623539m6963147566296146480m477101460960849173apple-converted-space"> </span></span><u></u><u></u></p>
<p class="m_-7912318491967259984m-4986576493345623539m6963147566296146480m477101460960849173p1"><span class="m_-7912318491967259984m-4986576493345623539m6963147566296146480m477101460960849173apple-converted-space"><span style="color:black">
</span></span><span style="color:black">1 KSP Residual norm 2.120375403775e-01<span class="m_-7912318491967259984m-4986576493345623539m6963147566296146480m477101460960849173apple-converted-space"> </span></span><u></u><u></u></p>
<p class="m_-7912318491967259984m-4986576493345623539m6963147566296146480m477101460960849173p1"><span class="m_-7912318491967259984m-4986576493345623539m6963147566296146480m477101460960849173apple-converted-space"><span style="color:black">
</span></span><span style="color:black">2 KSP Residual norm 5.155439334511e-03<span class="m_-7912318491967259984m-4986576493345623539m6963147566296146480m477101460960849173apple-converted-space"> </span></span><u></u><u></u></p>
<p class="m_-7912318491967259984m-4986576493345623539m6963147566296146480m477101460960849173p1"><span class="m_-7912318491967259984m-4986576493345623539m6963147566296146480m477101460960849173apple-converted-space"><span style="color:black">
</span></span><span style="color:black">3 KSP Residual norm 1.394364169369e-04<span class="m_-7912318491967259984m-4986576493345623539m6963147566296146480m477101460960849173apple-converted-space"> </span></span><u></u><u></u></p>
<p class="m_-7912318491967259984m-4986576493345623539m6963147566296146480m477101460960849173p1"><span class="m_-7912318491967259984m-4986576493345623539m6963147566296146480m477101460960849173apple-converted-space"><span style="color:black">
</span></span><span style="color:black">4 KSP Residual norm 9.233543407204e-06<span class="m_-7912318491967259984m-4986576493345623539m6963147566296146480m477101460960849173apple-converted-space"> </span></span><u></u><u></u></p>
<p class="m_-7912318491967259984m-4986576493345623539m6963147566296146480m477101460960849173p1"><span class="m_-7912318491967259984m-4986576493345623539m6963147566296146480m477101460960849173apple-converted-space"><span style="color:black">
</span></span><span style="color:black">Linear solve converged due to CONVERGED_RTOL iterations 4</span><u></u><u></u></p>
<p class="m_-7912318491967259984m-4986576493345623539m6963147566296146480m477101460960849173p2"><span style="color:black"> </span><u></u><u></u></p>
<p class="m_-7912318491967259984m-4986576493345623539m6963147566296146480m477101460960849173p1"><span class="m_-7912318491967259984m-4986576493345623539m6963147566296146480m477101460960849173apple-converted-space"><span style="color:black">
</span></span><span style="color:black">Line search: Using full step: fnorm 3.890991210938e-03 gnorm 7.701511565083e-06</span><u></u><u></u></p>
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</span></span><span style="color:black">1 SNES Function norm 7.701511565083e-06<span class="m_-7912318491967259984m-4986576493345623539m6963147566296146480m477101460960849173apple-converted-space"> </span></span><u></u><u></u></p>
<p class="m_-7912318491967259984m-4986576493345623539m6963147566296146480m477101460960849173p1"><span class="m_-7912318491967259984m-4986576493345623539m6963147566296146480m477101460960849173apple-converted-space"><span style="color:black">
</span></span><span style="color:black">0 KSP Residual norm 5.630229687829e-03<span class="m_-7912318491967259984m-4986576493345623539m6963147566296146480m477101460960849173apple-converted-space"> </span></span><u></u><u></u></p>
<p class="m_-7912318491967259984m-4986576493345623539m6963147566296146480m477101460960849173p1"><span class="m_-7912318491967259984m-4986576493345623539m6963147566296146480m477101460960849173apple-converted-space"><span style="color:black">
</span></span><span style="color:black">1 KSP Residual norm 1.030475601271e-04<span class="m_-7912318491967259984m-4986576493345623539m6963147566296146480m477101460960849173apple-converted-space"> </span></span><u></u><u></u></p>
<p class="m_-7912318491967259984m-4986576493345623539m6963147566296146480m477101460960849173p1"><span class="m_-7912318491967259984m-4986576493345623539m6963147566296146480m477101460960849173apple-converted-space"><span style="color:black">
</span></span><span style="color:black">2 KSP Residual norm 2.576454714319e-06<span class="m_-7912318491967259984m-4986576493345623539m6963147566296146480m477101460960849173apple-converted-space"> </span></span><u></u><u></u></p>
<p class="m_-7912318491967259984m-4986576493345623539m6963147566296146480m477101460960849173p1"><span class="m_-7912318491967259984m-4986576493345623539m6963147566296146480m477101460960849173apple-converted-space"><span style="color:black">
</span></span><span style="color:black">3 KSP Residual norm 6.669316846898e-08<span class="m_-7912318491967259984m-4986576493345623539m6963147566296146480m477101460960849173apple-converted-space"> </span></span><u></u><u></u></p>
<p class="m_-7912318491967259984m-4986576493345623539m6963147566296146480m477101460960849173p1"><span class="m_-7912318491967259984m-4986576493345623539m6963147566296146480m477101460960849173apple-converted-space"><span style="color:black">
</span></span><span style="color:black">4 KSP Residual norm 3.215810984829e-09<span class="m_-7912318491967259984m-4986576493345623539m6963147566296146480m477101460960849173apple-converted-space"> </span></span><u></u><u></u></p>
<p class="m_-7912318491967259984m-4986576493345623539m6963147566296146480m477101460960849173p1"><span class="m_-7912318491967259984m-4986576493345623539m6963147566296146480m477101460960849173apple-converted-space"><span style="color:black">
</span></span><span style="color:black">Linear solve converged due to CONVERGED_RTOL iterations 4</span><u></u><u></u></p>
<p class="m_-7912318491967259984m-4986576493345623539m6963147566296146480m477101460960849173p2"><span style="color:black"> </span><u></u><u></u></p>
<p class="m_-7912318491967259984m-4986576493345623539m6963147566296146480m477101460960849173p1"><span class="m_-7912318491967259984m-4986576493345623539m6963147566296146480m477101460960849173apple-converted-space"><span style="color:black">
</span></span><span style="color:black">Line search: gnorm after quadratic fit 1.805500533481e-05</span><u></u><u></u></p>
<p class="m_-7912318491967259984m-4986576493345623539m6963147566296146480m477101460960849173p1"><span class="m_-7912318491967259984m-4986576493345623539m6963147566296146480m477101460960849173apple-converted-space"><span style="color:black">
</span></span><span style="color:black">Line search: Cubic step no good, shrinking lambda, current gnorm 2.563759884284e-05 lambda=3.0804668685096816e-02</span><u></u><u></u></p>
<p class="m_-7912318491967259984m-4986576493345623539m6963147566296146480m477101460960849173p1"><span class="m_-7912318491967259984m-4986576493345623539m6963147566296146480m477101460960849173apple-converted-space"><span style="color:black">
</span></span><span style="color:black">Line search: Cubic step no good, shrinking lambda, current gnorm 3.332721829751e-05 lambda=3.0804668685096817e-03</span><u></u><u></u></p>
<p class="m_-7912318491967259984m-4986576493345623539m6963147566296146480m477101460960849173p1"><span class="m_-7912318491967259984m-4986576493345623539m6963147566296146480m477101460960849173apple-converted-space"><span style="color:black">
</span></span><span style="color:black">Line search: Cubic step no good, shrinking lambda, current gnorm 4.102754045833e-05 lambda=3.0804668685096822e-04</span><u></u><u></u></p>
<p class="m_-7912318491967259984m-4986576493345623539m6963147566296146480m477101460960849173p1"><span class="m_-7912318491967259984m-4986576493345623539m6963147566296146480m477101460960849173apple-converted-space"><span style="color:black">
</span></span><span style="color:black">Line search: Cubic step no good, shrinking lambda, current gnorm 4.872893294880e-05 lambda=3.0804668685096822e-05</span><u></u><u></u></p>
<p class="m_-7912318491967259984m-4986576493345623539m6963147566296146480m477101460960849173p1"><span class="m_-7912318491967259984m-4986576493345623539m6963147566296146480m477101460960849173apple-converted-space"><span style="color:black">
</span></span><span style="color:black">Line search: Cubic step no good, shrinking lambda, current gnorm 5.643043250787e-05 lambda=3.0804668685096822e-06</span><u></u><u></u></p>
<p class="m_-7912318491967259984m-4986576493345623539m6963147566296146480m477101460960849173p1"><span class="m_-7912318491967259984m-4986576493345623539m6963147566296146480m477101460960849173apple-converted-space"><span style="color:black">
</span></span><span style="color:black">Line search: Cubic step no good, shrinking lambda, current gnorm 6.413194279696e-05 lambda=3.0804668685096827e-07</span><u></u><u></u></p>
<p class="m_-7912318491967259984m-4986576493345623539m6963147566296146480m477101460960849173p1"><span class="m_-7912318491967259984m-4986576493345623539m6963147566296146480m477101460960849173apple-converted-space"><span style="color:black">
</span></span><span style="color:black">Line search: Cubic step no good, shrinking lambda, current gnorm 7.183345417492e-05 lambda=3.0804668685096828e-08</span><u></u><u></u></p>
<p class="m_-7912318491967259984m-4986576493345623539m6963147566296146480m477101460960849173p1"><span class="m_-7912318491967259984m-4986576493345623539m6963147566296146480m477101460960849173apple-converted-space"><span style="color:black">
</span></span><span style="color:black">Line search: Cubic step no good, shrinking lambda, current gnorm 7.953496567312e-05 lambda=3.0804668685096829e-09</span><u></u><u></u></p>
<p class="m_-7912318491967259984m-4986576493345623539m6963147566296146480m477101460960849173p1"><span class="m_-7912318491967259984m-4986576493345623539m6963147566296146480m477101460960849173apple-converted-space"><span style="color:black">
</span></span><span style="color:black">Line search: Cubic step no good, shrinking lambda, current gnorm 8.723647719173e-05 lambda=3.0804668685096831e-10</span><u></u><u></u></p>
<p class="m_-7912318491967259984m-4986576493345623539m6963147566296146480m477101460960849173p1"><span class="m_-7912318491967259984m-4986576493345623539m6963147566296146480m477101460960849173apple-converted-space"><span style="color:black">
</span></span><span style="color:black">Line search: Cubic step no good, shrinking lambda, current gnorm 9.493798871875e-05 lambda=3.0804668685096832e-11</span><u></u><u></u></p>
<p class="m_-7912318491967259984m-4986576493345623539m6963147566296146480m477101460960849173p1"><span class="m_-7912318491967259984m-4986576493345623539m6963147566296146480m477101460960849173apple-converted-space"><span style="color:black">
</span></span><span style="color:black">Line search: Cubic step no good, shrinking lambda, current gnorm 1.026395002516e-04 lambda=3.0804668685096835e-12</span><u></u><u></u></p>
<p class="m_-7912318491967259984m-4986576493345623539m6963147566296146480m477101460960849173p1"><span class="m_-7912318491967259984m-4986576493345623539m6963147566296146480m477101460960849173apple-converted-space"><span style="color:black">
</span></span><span style="color:black">Line search: Cubic step no good, shrinking lambda, current gnorm 1.103410117889e-04 lambda=3.0804668685096835e-13</span><u></u><u></u></p>
<p class="m_-7912318491967259984m-4986576493345623539m6963147566296146480m477101460960849173p1"><span class="m_-7912318491967259984m-4986576493345623539m6963147566296146480m477101460960849173apple-converted-space"><span style="color:black">
</span></span><span style="color:black">Line search: unable to find good step length! After 12 tries<span class="m_-7912318491967259984m-4986576493345623539m6963147566296146480m477101460960849173apple-converted-space"> </span></span><u></u><u></u></p>
<p class="m_-7912318491967259984m-4986576493345623539m6963147566296146480m477101460960849173p1"><span class="m_-7912318491967259984m-4986576493345623539m6963147566296146480m477101460960849173apple-converted-space"><span style="color:black">
</span></span><span style="color:black">Line search: fnorm=7.7015115650831560e-06, gnorm=1.1034101178892401e-04, ynorm=6.2052357872955976e-03, minlambda=9.9999999999999998e-13, lambda=3.0804668685096835e-13, initial slope=-5.9313318983096354e-11</span><u></u><u></u></p>
<p class="m_-7912318491967259984m-4986576493345623539m6963147566296146480m477101460960849173p1"><span style="color:black">Nonlinear solve did not converge due to DIVERGED_LINE_SEARCH iterations 1</span><u></u><u></u></p>
<p class="MsoNormal"> <u></u><u></u></p>
<p class="MsoNormal"> <u></u><u></u></p>
<p class="MsoNormal">Thank you for your help.<u></u><u></u></p>
<p class="MsoNormal"> <u></u><u></u></p>
<p class="MsoNormal">Kind regards,<u></u><u></u></p>
<p class="MsoNormal">Karthik.<u></u><u></u></p>
<p class="MsoNormal"> <u></u><u></u></p>
<div>
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<p class="MsoNormal">-- <u></u><u></u></p>
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<p class="MsoNormal"><b><span style="font-size:10.5pt;font-family:Arial,sans-serif;color:rgb(45,45,98)">Dr. Karthik Chockalingam</span></b><u></u><u></u></p>
<p class="MsoNormal"><span style="font-size:10.5pt;font-family:Arial,sans-serif;color:black">Senior Research Software Engineer</span><u></u><u></u></p>
<p class="MsoNormal"><span style="font-size:10.5pt;font-family:Arial,sans-serif;color:black">High Performance Systems Engineering Group</span><u></u><u></u></p>
<p class="MsoNormal"><span style="font-size:10.5pt;font-family:Arial,sans-serif;color:black">Hartree Centre | Science and Technology Facilities Council</span><u></u><u></u></p>
<p class="MsoNormal"><a href="mailto:karthikeyan.chockalingam@stfc.ac.uk" target="_blank"><span style="font-size:10.5pt;font-family:Arial,sans-serif;color:rgb(5,99,193)">karthikeyan.chockalingam@stfc.ac.uk</span></a><u></u><u></u></p>
<p class="MsoNormal"><span style="font-size:12pt;font-family:"Times New Roman",serif;color:black"> </span><span style="font-size:10.5pt;font-family:Arial,sans-serif;color:rgb(65,65,65)"> </span><u></u><u></u></p>
<p class="MsoNormal"><b><span style="font-size:10.5pt;font-family:Arial,sans-serif;color:rgb(65,65,65)"> </span></b><b><span style="font-size:12pt;font-family:"Times New Roman",serif;color:rgb(31,73,125)">Error!
Filename not specified.</span></b><u></u><u></u></p>
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<p class="MsoNormal"> <u></u><u></u></p>
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<span class="m_-7912318491967259984m-4986576493345623539m6963147566296146480gmailsignatureprefix">-- </span>
<u></u><u></u></p>
<div>
<p class="MsoNormal">Stefano<u></u><u></u></p>
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</blockquote>
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<p class="MsoNormal"> <u></u><u></u></p>
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<p class="MsoNormal"><span class="m_-7912318491967259984m-4986576493345623539gmailsignatureprefix">--
</span><u></u><u></u></p>
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<p class="MsoNormal">What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead.<br>
-- Norbert Wiener<u></u><u></u></p>
</div>
<div>
<p class="MsoNormal"> <u></u><u></u></p>
</div>
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<p class="MsoNormal"><a href="http://www.cse.buffalo.edu/~knepley/" target="_blank">https://www.cse.buffalo.edu/~knepley/</a><u></u><u></u></p>
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<p class="MsoNormal"><u></u> <u></u></p>
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<p class="MsoNormal"><span class="m_-7912318491967259984gmailsignatureprefix">-- </span><u></u><u></u></p>
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<div>
<div>
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<p class="MsoNormal">What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead.<br>
-- Norbert Wiener<u></u><u></u></p>
</div>
<div>
<p class="MsoNormal"><u></u> <u></u></p>
</div>
<div>
<p class="MsoNormal"><a href="http://www.cse.buffalo.edu/~knepley/" target="_blank">https://www.cse.buffalo.edu/~knepley/</a><u></u><u></u></p>
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</div></blockquote></div><br clear="all"><div><br></div><span class="gmail_signature_prefix">-- </span><br><div dir="ltr" class="gmail_signature"><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><div>What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead.<br>-- Norbert Wiener</div><div><br></div><div><a href="http://www.cse.buffalo.edu/~knepley/" target="_blank">https://www.cse.buffalo.edu/~knepley/</a><br></div></div></div></div></div></div></div></div>