<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<style type="text/css" style="display:none;"><!-- P {margin-top:0;margin-bottom:0;} --></style>
</head>
<body dir="ltr">
<div id="divtagdefaultwrapper" style="font-size:12pt;color:#000000;font-family:Calibri,Helvetica,sans-serif;" dir="ltr">
<div id="divtagdefaultwrapper" dir="ltr" style="font-size: 12pt; color: rgb(0, 0, 0); font-family: Calibri, Helvetica, sans-serif, "EmojiFont", "Apple Color Emoji", "Segoe UI Emoji", NotoColorEmoji, "Segoe UI Symbol", "Android Emoji", EmojiSymbols;">
<p>Hi Taiko,</p>
<p><br>
</p>
<p>I will (partly) skip the first part of your message and let others reply on that, as I don't have experience with NS simulations.</p>
<p><br>
</p>
<p>Regarding the gravitational wave extraction, I think you are accessing the data correctly (your example gives the time series for one mode at one radius), and there should be more than one element in general. From your parameter file, it seems the output
should go to an ascii file (it's the default), so you can double check in that file too.</p>
<p>However, since you have `<span>Multipole::out_every = 128</span>`, does your simulation reach iteration 128 and later? In particular, because you're getting nans at iteration 0, does the simulation actually go past t=0? Given what you're saying, I guess
your single element of `<span>SimDir.gws[100][(2,2)].x</span>` is 0 (i.e t=0).</p>
<p><br>
</p>
<p>Best,</p>
<p><br>
</p>
<p>Jordan</p>
<p><br>
</p>
<p><br>
</p>
</div>
<hr tabindex="-1" style="display:inline-block; width:98%">
<div id="divRplyFwdMsg" dir="ltr"><font face="Calibri, sans-serif" color="#000000" style="font-size:11pt"><b>From:</b> Users <users-bounces@einsteintoolkit.org> on behalf of MAKINO Taiki via Users <users@einsteintoolkit.org><br>
<b>Sent:</b> Thursday, July 2, 2026 12:39:00 AM<br>
<b>To:</b> users@einsteintoolkit.org<br>
<b>Subject:</b> [Users] Question about IllinoisGRMHD C2P failure and kuibit Psi4 extraction</font>
<div> </div>
</div>
<div>
<table style="width:100%; font-family:Arial; font-size:10pt">
<tbody>
<tr>
<td style="width:5px; background-color:#ffb900"></td>
<td style="padding:5px 5px; background-color:#FFFFE0">
<p></p>
<strong>CUIDADO:</strong> Email de um sistema externo. Cuidado com links, anexos e pedidos de dados/senhas.<br>
<strong>CAUTION:</strong> Email from an external system. Be careful with links, attachments, and requests for data/passwords.
</td>
</tr>
</tbody>
</table>
<div>
<div style="direction:ltr; font-family:Aptos,Arial,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">
<span style="text-transform:none">Dear Einstein Toolkit Users,</span></div>
<div style="direction:ltr; text-align:left; text-indent:0px; text-transform:none; font-family:Aptos,Arial,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">
<br>
</div>
<div style="direction:ltr; text-align:left; text-indent:0px; text-transform:none; font-family:Aptos,Arial,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">
I am a new Einstein Toolkit user, and I have some questions about a BNS simulation.</div>
<div style="direction:ltr; text-align:left; text-indent:0px; text-transform:none; font-family:Aptos,Arial,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">
<br>
</div>
<div style="direction:ltr; text-align:left; text-indent:0px; text-transform:none; font-family:Aptos,Arial,Helvetica,sans-serif; font-size:12pt">
<span style="color:rgb(0,0,0)">I am trying to run a BNS simulation using bns.par, which I downloaded from Einstein Toolkit Gallery (</span><span style="color:rgb(0,120,212)"><a href="https://einsteintoolkit.org/gallery/bns/index.html" title="https://einsteintoolkit.org/gallery/bns/index.html" style="color:rgb(0,120,212)">https://einsteintoolkit.org/gallery/bns/index.html</a></span><span style="color:rgb(0,0,0)">)
and slightly modified.</span></div>
<div style="direction:ltr; text-align:left; text-indent:0px; text-transform:none; font-family:Aptos,Arial,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">
<br>
</div>
<div style="text-align:left; text-indent:0px; text-transform:none; font-family:Aptos,Arial,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">
I can successfully create and submit the simulation but the following message appears during the simulation:</div>
<div style="direction:ltr; text-align:left; text-indent:0px; text-transform:none; font-family:Aptos,Arial,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">
<br>
</div>
<div style="direction:ltr; text-align:left; text-indent:0px; text-transform:none; margin-left:40px; font-family:Aptos,Arial,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">
INFO (IllinoisGRMHD): C2P: Iter. # 0, Lev: 5 NumPts= 132300 | Backups: 0 0 0 | Fixes: VL= 0 rho*= 0 Averaged pts = 38250 Font1D 38250 | Failures: 2250 InHoriz= 0 / 0 | 1.00 iters/gridpt Error, Sum: rho 6.378e-08, 2.433e-05 | tau nan, -nan | Sx nan, nan | Sy
nan, nan | Sz nan, nan</div>
<div style="direction:ltr; text-align:left; text-indent:0px; text-transform:none; margin-left:40px; font-family:Aptos,Arial,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">
<br>
</div>
<div style="direction:ltr; text-align:left; text-indent:0px; text-transform:none; margin-left:0px; font-family:Aptos,Arial,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">
To investigate this problem, I added the following parameters:</div>
<div style="direction:ltr; text-align:left; text-indent:0px; text-transform:none; margin-left:40px; font-family:Aptos,Arial,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">
Multipole::interpolator_name = "Lagrange polynomial interpolation"<br>
Multipole::interpolator_pars = "order=4"</div>
<div style="direction:ltr; text-align:left; text-indent:0px; text-transform:none; margin-left:0px; font-family:Aptos,Arial,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">
<br>
</div>
<div style="direction:ltr; text-align:left; text-indent:0px; text-transform:none; margin-left:0px; font-family:Aptos,Arial,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">
I also changed the parameter Driver::ghost_size from 3 to 4, but the same error occurred.</div>
<div style="direction:ltr; text-align:left; text-indent:0px; text-transform:none; margin-left:0px; font-family:Aptos,Arial,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">
<br>
</div>
<div style="direction:ltr; text-align:left; text-indent:0px; text-transform:none; margin-left:0px; font-family:Aptos,Arial,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">
I would like to ask:</div>
<ul style="direction:ltr; text-align:left; margin-top:0px; margin-bottom:0px; list-style-type:disc">
<li style="font-family:"Yu Gothic Regular"; font-size:12pt; color:rgb(0,0,0); text-indent:0px">
<div><span style="text-transform:none">What could cause tau, Sx, Sy, and Sz to become NaN in this situation?</span></div>
</li><li style="font-family:"Yu Gothic Regular"; font-size:12pt; color:rgb(0,0,0); text-indent:0px">
<div><span style="text-transform:none">Does this indicate a failure of C2P conversion?</span></div>
</li><li style="font-family:"Yu Gothic Regular"; font-size:12pt; color:rgb(0,0,0); text-indent:0px">
<div><span style="text-transform:none">Are there any parameter settings or initial data that I should check first?</span></div>
</li></ul>
<div style="direction:ltr; text-align:left; text-indent:0px; text-transform:none; font-family:Aptos,Arial,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">
<br>
</div>
<div style="direction:ltr; text-align:left; text-indent:0px; text-transform:none; font-family:Aptos,Arial,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">
Additionally, I have another question. When I use kuibit to extract Psi4, I expected to obtain the full time series (or all available modes) but the returned object contains only one element, for example, </div>
<div style="direction:ltr; text-align:left; text-indent:0px; text-transform:none; font-family:Aptos,Arial,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">
SimDir.gws[100][(2,2)].y=[-9.79586237e-15-5.27476073e-14j].</div>
<div style="direction:ltr; text-align:left; text-indent:0px; text-transform:none; font-family:Aptos,Arial,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">
<br>
</div>
<div style="direction:ltr; text-align:left; text-indent:0px; text-transform:none; font-family:Aptos,Arial,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">
Other attributes such as</div>
<div style="direction:ltr; text-align:left; text-indent:0px; text-transform:none; font-family:Aptos,Arial,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">
SimDir.gws[100][(2,2)].x </div>
<div style="direction:ltr; text-align:left; text-indent:0px; text-transform:none; font-family:Aptos,Arial,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">
<br>
</div>
<div style="direction:ltr; text-align:left; text-indent:0px; text-transform:none; font-family:Aptos,Arial,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">
also contain only one element. Is this a correct behavior or could it indicate a problem with my .par file? </div>
<div style="direction:ltr; text-align:left; text-indent:0px; text-transform:none; font-family:Aptos,Arial,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">
<br>
</div>
<div style="direction:ltr; text-align:left; text-indent:0px; text-transform:none; font-family:Aptos,Arial,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">
For reference, I have attached my parameter file.</div>
<div style="direction:ltr; text-align:left; text-indent:0px; text-transform:none; font-family:Aptos,Arial,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">
<br>
</div>
<div style="direction:ltr; text-align:left; text-indent:0px; text-transform:none; font-family:Aptos,Arial,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">
Thank you very much for your time and any suggestions.</div>
<div style="direction:ltr; text-align:left; text-indent:0px; text-transform:none; font-family:Aptos,Arial,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">
<br>
</div>
<div style="direction:ltr; text-align:left; text-indent:0px; text-transform:none; font-family:Aptos,Arial,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">
Best regards,</div>
<div style="direction:ltr; text-align:left; text-indent:0px; text-transform:none; font-family:Aptos,Arial,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">
<br>
</div>
<p style="text-align:left; text-indent:0px; text-transform:none; margin-top:0px; margin-bottom:0px">
<span style="font-family:"Yu Gothic Regular"; font-size:12pt; color:rgb(0,0,0); text-transform:none">Taiki Makino</span></p>
<p style="text-align:left; text-indent:0px; text-transform:none; margin-top:0px; margin-bottom:0px">
<span style="font-family:"Yu Gothic Regular"; font-size:12pt; color:rgb(0,0,0)">Graduate School of Science, Nagoya University</span></p>
<p style="text-align:left; text-indent:0px; text-transform:none; margin-top:0px; margin-bottom:0px">
<span style="font-family:Aptos,Aptos_EmbeddedFont,Aptos_MSFontService,Calibri,Helvetica,sans-serif; font-size:12pt; color:rgb(0,120,212)"><a href="mailto:makino.taiki.g6@s.mail.nagoya-u.ac.jp" class="ms-outlook-linkify" title="mailto:makino.taiki.g6@s.mail.nagoya-u.ac.jp" style="color:rgb(0,120,212); margin-top:0px; margin-bottom:0px"><u>makino</u>.taiki.g6@s.mail.nagoya-u.ac.jp</a></span></p>
<div style="direction:ltr; text-align:left; text-indent:0px; text-transform:none; font-family:Aptos,Aptos_EmbeddedFont,Aptos_MSFontService,Calibri,Helvetica,sans-serif; font-size:12pt; color:rgb(0,120,212)">
<br>
</div>
<div style="font-family:"Yu Gothic Regular"; color:rgb(33,33,33)">取得 <span style="color:rgb(0,120,212)">
<a href="https://aka.ms/GetOutlookForMac" title="https://aka.ms/GetOutlookForMac" style="color:rgb(0,120,212)">Outlook for Mac</a></span></div>
<div style="direction:ltr; font-family:Aptos,Arial,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">
<br>
</div>
<div style="direction:ltr; font-family:Aptos,Arial,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">
<br>
</div>
<div id="ms-outlook-mobile-signature">
<div class="MsoNormal" style="direction:ltr">取得 <a href="https://aka.ms/GetOutlookForMac">
Outlook for Mac</a></div>
</div>
</div>
</div>
</div>
</body>
</html>