<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><br><div><div>On Jun 22, 2011, at 10:26 AM, Jed Brown wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><div class="gmail_quote">On Wed, Jun 22, 2011 at 16:58, Qian Zhu <span dir="ltr"><<a href="mailto:qzhu@mcs.anl.gov">qzhu@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;">
For ex5, par=xxx, using "-ksp_type gmres -pc_type ilu" will make the solution converge while using "-ksp_type cg -pc_type jacobi" cannot (all ksp's and pc's are just randomly picked...they may not make sense).</blockquote>
<div><br></div><div>boundary conditions are not symmetric in this example</div><div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;"> What would this "xxx" value be? Or is there any input parameters I am missing out for these applications?</blockquote>
</div><br><div>look at snes ex19 and use -lidvelocity 100 -grashof 1e5 if you are looking for something that doesn't converge. Or try a Stokes problem.</div>
</blockquote><br></div><div>Thanks for the reply, Jed. I worked on ex27 so I know setting certain values for the input parameters can make the case converge/non-converge...I am just wondering whether this is also true with ex5 and ex20 (We picked them for other interesting characteristics). Which examples are solving the Stokers problem?</div><div><br></div><div>Thanks a lot! </div><br><div>
<span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; font-size: medium; ">Qian Zhu, Ph.D.<br>Mathematics and Computer Science Division<br>Argonne National Laboratory<br>9700 S.Cass Avenue<br>Argonne, IL 60439-4844<br>Phone: 630-252-0086</span>
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