<div dir="ltr"><div dir="ltr">On Thu, Sep 17, 2020 at 2:54 PM Alexander B Prescott <<a href="mailto:alexprescott@email.arizona.edu">alexprescott@email.arizona.edu</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 dir="ltr"><div dir="ltr">Thank you all for your input. Matt is right, I cannot batch as this formulation must be done sequentially. <div><br></div><div>>> Sounds a bit like a non-smoother (Gauss-Seidel type), speculating based on these few words.</div><div><br></div><div>Barry, it is similar to a Gauss-Seidel solver in that solution updates from previous solves are used in the most recent Newton solve, though I'm not exactly sure what you mean by "non-smoother".</div></div></div></blockquote><div><br></div><div>He means a nonlinear smoother. You iterate over your domain solving small nonlinear problems in order to get closer to the solution</div><div>of the big nonlinear problem. Depending on what you are doing, it might be possible to decouple these, which would likely be much</div><div>more efficient.</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 dir="ltr"><div dir="ltr"><div>Best,</div><div>Alexander</div></div><div><br></div><div><br></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Thu, Sep 17, 2020 at 6:06 AM Matthew Knepley <<a href="mailto:knepley@gmail.com" target="_blank">knepley@gmail.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><p style="text-align:center"><font color="red"><strong>External Email</strong><br></font></p><div dir="ltr"><div dir="ltr">On Thu, Sep 17, 2020 at 12:23 AM Jed Brown <<a href="mailto:jed@jedbrown.org" target="_blank">jed@jedbrown.org</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">Alexander B Prescott <<a href="mailto:alexprescott@email.arizona.edu" target="_blank">alexprescott@email.arizona.edu</a>> writes:<br>
<br>
>> Are the problems of varying nonlinearity, that is will some converge<br>
>> with say a couple of Newton iterations while others require more, say 8 or<br>
>> more Newton steps?<br>
>><br>
> The nonlinearity should be pretty similar, the problem setup is the same at<br>
> every node but the global domain needs to be traversed in a specific order.<br>
<br>
<br>
It sounds like you may have a Newton solver now for each individual problem? If so, could you make a histogram of number of iterations necessary to solve? Does it have a long tail or does every problem take 3 and 4 iterations (for example).<br>
<br>
If there is no long tail, then you can batch. If there is a long tail, you really want a solver that does one problem at a time, or a more dynamic system that checks which have completed and shrinks the active problem down. (That complexity has a development and execution time cost.)<br>
</blockquote></div><br clear="all"><div>He cannot batch if the solves are sequential, as he says above.</div><div><br></div><div> Matt</div><div><br></div>-- <br><div dir="ltr"><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>
</blockquote></div><br clear="all"><div><br></div>-- <br><div dir="ltr"><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><div style="font-size:12.8px"><span style="font-family:arial,sans-serif">Alexander</span><span style="font-family:arial,sans-serif"> </span><span style="font-family:arial,sans-serif">Prescott</span><br></div><div style="font-size:12.8px"><span style="font-family:arial,sans-serif"><a href="mailto:alexprescott@email.arizona.edu" target="_blank">alexprescott@email.arizona.edu</a></span></div><div style="font-size:12.8px"><div style="font-family:arial,sans-serif"><span>PhD</span> <span>Candidate</span>, The University of Arizona</div><div style="font-family:arial,sans-serif">Department of Geosciences</div><div style="font-family:arial,sans-serif">1040 E. 4th Street</div><div style="font-family:arial,sans-serif">Tucson, AZ, 85721</div></div></div></div></div></div></div></div>
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</blockquote></div><br clear="all"><div><br></div>-- <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>