<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; color: rgb(0, 0, 0); font-size: 14px; font-family: Calibri, sans-serif; "><div><div>Hi Erik.</div><div><br></div><div>Five minutes after hitting "Send", I thought to look at the interpolation scheme. It looks like I might have been using a local AEILocalInterp variation for the more recent run. Testing now ...</div><div><br></div><div>Bernard </div></div><div><br></div><span id="OLK_SRC_BODY_SECTION"><div style="font-family:Calibri; font-size:11pt; text-align:left; color:black; BORDER-BOTTOM: medium none; BORDER-LEFT: medium none; PADDING-BOTTOM: 0in; PADDING-LEFT: 0in; PADDING-RIGHT: 0in; BORDER-TOP: #b5c4df 1pt solid; BORDER-RIGHT: medium none; PADDING-TOP: 3pt"><span style="font-weight:bold">From: </span> Erik Schnetter <<a href="mailto:schnetter@cct.lsu.edu">schnetter@cct.lsu.edu</a>><br><span style="font-weight:bold">Date: </span> Friday, November 30, 2012 11:34 AM<br><span style="font-weight:bold">To: </span> Bernard Kelly <<a href="mailto:bernard.j.kelly@nasa.gov">bernard.j.kelly@nasa.gov</a>><br><span style="font-weight:bold">Cc: </span> Ian Hinder <<a href="mailto:ian.hinder@aei.mpg.de">ian.hinder@aei.mpg.de</a>>, "<a href="mailto:users@einsteintoolkit.org">users@einsteintoolkit.org</a>" <<a href="mailto:users@einsteintoolkit.org">users@einsteintoolkit.org</a>><br><span style="font-weight:bold">Subject: </span> Re: [Users] **large** amplitude changes in WFs from Curie "bbh" parfiles when run in ET_2012_05<br></div><div><br></div><div><meta http-equiv="Content-Type" content="text/html; charset=utf-8"><div>
Bernard
<div><br></div><div>Maybe there is a change in the interpolation scheme used for the multipole extraction? There may have been some changes regarding how buffer points are treated.</div><div><br></div><div>-erik</div><div><br></div><div class="gmail_extra"><br><br><div class="gmail_quote">On Fri, Nov 30, 2012 at 11:07 AM, Kelly, Bernard J. (GSFC-660.0)[UNIVERSITY OF MARYLAND BALTIMORE COUNTY]
<span dir="ltr"><<a href="mailto:bernard.j.kelly@nasa.gov" target="_blank">bernard.j.kelly@nasa.gov</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
Hi Ian and others. Coming back to this unresolved issue ...<br><br>
I've looked at 1D metric files from a fairly advanced point in the<br>
evolution, and can see no differences in the metric components from the<br>
two evolutions. It's difficult to do precise differencing, since the grids<br>
are not commensurate, as pointed out before.<br><br>
More directly, I've looked at the WeylScal4 waveforms along the coordinate<br>
axes, and they show no sign of the amplitude discrepancy. Attached is the<br>
output from psi4 along the x-axis at around 120M in the evolution (Med<br>
resolution).<br><br>
So it looks like the change is in the Multipole extraction. Diffing the<br>
two Multipole thorns (and ignoring test-suite file changes), I only see<br>
minor changes in the schedule.ccl:<br><br>
8c8<br>
< schedule Multipole_Calc at CCTK_ANALYSIS after (calc_np,PsiKadelia)<br>
---<br>
> schedule Multipole_Calc at CCTK_ANALYSIS after<br>
>(calc_np,PsiKadelia,Accelerator_CopyBack)<br><br><br>
Again: has anyone run the Curie-era paper's "bbh" parameter files with a<br>
later release of ET and obtained *exactly* the same WF amplitudes? Or a<br>
difference within 1%?<br><br>
Bernard<br><br>
On 11/9/12 1:24 PM, "Kelly, Bernard J. (GSFC-660.0)[UNIVERSITY OF MARYLAND<br><div class="HOEnZb"><div class="h5">BALTIMORE COUNTY]" <<a href="mailto:bernard.j.kelly@nasa.gov">bernard.j.kelly@nasa.gov</a>> wrote:<br><br>
>Hi Ian. Thanks for the diagnostic suggestions.<br>
><br>
><br>
>On 11/7/12 3:59 PM, "Ian<br>
>Hinder" <<a href="mailto:ian.hinder@aei.mpg.de">ian.hinder@aei.mpg.de</a>> wrote:<br>
><br>
>><br>
>>On 7 Nov 2012, at 20:29, "Kelly,<br>
>Bernard J. (GSFC-660.0)[UNIVERSITY OF<br>
>>MARYLAND BALTIMORE COUNTY]"<br>
><<a href="mailto:bernard.j.kelly@nasa.gov">bernard.j.kelly@nasa.gov</a>> wrote:<br>
>><br>
>>> Hi. This may be related to something<br>
>Yosef brought up back in July<br>
>>> ["Differences in results ..." from 26<br>
>July], but I'm seeing sizable<br>
>>> differences in WF amplitudes from Multipole<br>
>when running the parameter<br>
>>> files for the ETK paper (Loeffler et al.).<br>
>>><br>
>>> Specifically, if I take the parameter file<br>
>>><br>
>>><br>
><Cactus>/par/arXiv:1111.3344/bbh/BBHMedHRes.par<br>
>>><br>
>>> ... and run it with a<br>
>Curie (ET_2011_05) executable, my r=30M (2,2) mode<br>
>>> has a peak magnitude<br>
>of just above 0.0027. Rerunning the same parameter<br>
>>> file with *no*<br>
>changes, using the current release, Lovelace<br>
>>>(ET_2012_05),<br>
>>> the same<br>
>peak amplitude is just above 0.00257 -- a drop of almost 5%.<br>
>>><br>
>>> Can<br>
>anyone tell me what might be going wrong? Is there some kind of<br>
>>>change<br>
>>><br>
>in default dissipation that could explain such a large discrepancy?<br>
>><br>
>>I<br>
>don't think so. McLachlan with its default parameters has always<br>
>>disabled<br>
>dissipation. We changed the default of apply_dissipation very<br>
>>recently<br>
>(i.e. after Lovelace) from "true" to "false" (and announced this<br>
>>on the<br>
>list), but the dissipation strength has always defaulted to<br>
>zero.<br>
>><br>
>>Dissipation in that parameter file is provided by the Dissipation<br>
>thorn,<br>
>>and it uses its default value of epsdiss = 0.2.<br>
>><br>
>>Could this be<br>
>related to the change in grid structure going from the<br>
>>"git" to the<br>
>"mercurial" version of Carpet? Are the grid structures the<br>
>>same? You can<br>
>output the grid structure to an ASCII file<br>
>using<br>
>><br>
>> Carpet::grid_coordinates_filename = "carpet-grid.asc"<br>
><br>
>I'm<br>
>attaching some excerpts from the carpet-grid-coordinates files of both<br>
>runs<br>
>("MedRes" version). They're snapshots from iterations 0, 609, and<br>
>2145. For<br>
>the latter two iterations, the grid does seem to be different in<br>
>the<br>
>y-direction (the only direction without a symmetry boundary), but only<br>
>for<br>
>certain refinement levels. The it=0 output is very different for the<br>
>two<br>
>cases; I'm not sure why.<br>
><br>
>Also, the Curie executable generated this<br>
>diagnostic information *far*<br>
>more frequently (every 32 iterations) than<br>
>Lovelace (every 384).<br>
>Obviously, the times I've chosen were common to<br>
>both.<br>
><br>
>><br>
>>Can you try to narrow down where the differences lie? For<br>
>example, you<br>
>>could look at the grid functions themselves, including one of<br>
>the evolved<br>
>>variables, one of the ADMBase variables, and also Psi4, to see<br>
>which are<br>
>>actually different.<br>
><br>
>I'll look at the 1D grid functions now, but<br>
>I wanted to get you this info<br>
>anyway.<br>
><br>
>Bernard<br>
><br>
><br><br></div></div><br>
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-- <br>
Erik Schnetter <<a href="mailto:schnetter@cct.lsu.edu" target="_blank">schnetter@cct.lsu.edu</a>><br><a href="http://www.perimeterinstitute.ca/personal/eschnetter/" target="_blank">http://www.perimeterinstitute.ca/personal/eschnetter/</a><br></div></div></div></span></body></html>