<html><head><meta http-equiv="Content-Type" content="text/html charset=us-ascii"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><br><div><div>On 22 Feb 2013, at 18:38, Kentaro Takami <<a href="mailto:kentaro.takami@aei.mpg.de">kentaro.takami@aei.mpg.de</a>> wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite">First of all, I should give you more information.<br><br>In my test, I don't use OpenMP. So I use only MPI.<br>I put dissipation only for spacetime variable such as gij, kij and so on.<br>I check these difference for GF in checkpoint files.<br>The difference appear from 2nd step of RK at 1st iteration,<br>where the difference are for last a few digit, but grow up as<br>increasing iterations.<br><br>In the following case we don't see difference.<br>*don't activate Dissipation thorn.<br>*using only 1 refinement level.<br>*using certain special dx=dy=dz.<br><br>Further strange behavior:<br>When I insert non-essential line such as "WRITE(*,*)" statement<br> in "apply_dissipation.F77", sometimes the difference is disappeared.<br>So, I doubted incorrect pointer position.<br></blockquote><div><br></div><div>Are you using sufficient ghost zones? </div><br><blockquote type="cite"><br><br>Hi, Frank,<br><br><blockquote type="cite"><blockquote type="cite">Finally I'm doubting the origin of the problem is "CactusNumerical/Dissipation",<br>because when I don't activate this thorn, the problem can be disappeared.<br></blockquote><br>This is interesting. So, you say you don't see random changes when<br>Dissipation isn't active, but you do when you activate it, and<br>everything else is the same? Which variables do you apply dissipation<br>to?<br></blockquote><br>Yes, if we don't use Dissipation, HDF5 checkpoint files can become exactly same,<br>at least my test case.<br>I added dissipation for the following variables:<br> ML_BSSN::ML_log_confac<br> ML_BSSN::ML_metric<br> ML_BSSN::ML_trace_curv<br> ML_BSSN::ML_curv<br> ML_BSSN::ML_Gamma<br> ML_BSSN::ML_lapse<br> ML_BSSN::ML_shift<br> ML_BSSN::ML_dtlapse<br> ML_BSSN::ML_dtshift<br><br><br>Kentaro<br>_______________________________________________<br>Users mailing list<br><a href="mailto:Users@einsteintoolkit.org">Users@einsteintoolkit.org</a><br>http://lists.einsteintoolkit.org/mailman/listinfo/users<br></blockquote></div><br><div apple-content-edited="true">
<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: -webkit-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; "><span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; 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; "><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; 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; "><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; 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; "><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div>-- </div><div>Ian Hinder</div><div><a href="http://numrel.aei.mpg.de/people/hinder">http://numrel.aei.mpg.de/people/hinder</a></div></div></span></div></span></div></span></span>
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