Users July 2021

users@lists.einsteintoolkit.org

20 participants
38 discussions

sim error
by Hamideh Hosseini 16 Jul '21

16 Jul '21

Hi all, I am installing ET on a cluster and keep getting this error: [test-vectors-4-SSE.cc.o] Error 1 make[2]: *** [make.checked] Error 2 make[1]: *** [/home/hhossei/Cactus/configs/sim/lib/libthorn_Vectors.a] Error 2 & Creating /home/hhossei/Cactus/configs/sim/lib/libthorn_Fortran.a make: *** [sim] Error 2 how can I fix that? regards, Hamideh

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Vectorization issue
by Hee Il Kim 15 Jul '21

15 Jul '21

Hi all, While examining different results from my colleague's, I found the vectorization option could develop misleading results. I seldom use the vectorization option but in the configuration file but he mixed up with mine and others leaving: VECTORISE = yes VECTORISE_ALIGNED_ARRAYS = no VECTORISE_INLINE = yes in the config file. I found these are default config options in recent simfactory optionlists. Instead, I used to use AVX but always adding e.g., "-fp-model precise" for value safeness. I attached two figures with the vectorization on/off. For the case of no vectorization, I tested it w/wo AVX and got the identical result. Hee Il

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BHNS Merger parfile
by Shamim Haque 15 Jul '21

15 Jul '21

Hello, I am trying to simulate a black hole - neutron star merger. Can someone point me to an example parameter file for such kind of simulations? Thanks and regards Shamim Haque Junior Research Fellow (JRF) Department of Physics IISER Bhopal

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Einstein Toolkit Meeting Reminder
by users＠einsteintoolkit.org 14 Jul '21

14 Jul '21

Hello, Please consider joining the weekly Einstein Toolkit phone call at 9:00 am US central time on Thursdays. For details on how to connect and what agenda items are to be discussed, use the link below. https://docs.einsteintoolkit.org/et-docs/Main_Page#Weekly_Users_Call --The Maintainers

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Changing the number of MPI processes on recovery using simfactory
by Konrad Topolski 14 Jul '21

14 Jul '21

Hi, I am currently trying to find what the optimal number of MPI processes is for my purposes. I have managed to change the number of MPI processes when restarting a simulation from a checkpoint - but using the bare executable, not simfactory. Now, I would like to learn how to do it in simfactory. I have learned that to successfully steer the number of threads per 1 MPI process (which, combined with a total number of threads requested, yields the total number of MPI processes), I change the num-thread variable in the machine.ini file. This is probably (certainly?) suboptimal, so if there's a proper way, I'd like to learn it. I submit/recover simulations via . /simfactory/bin/sim submit <sim_name> --parfile <parfile_name> --recover --procs NUM_PROCS --machine=okeanos --configuration=okeanos If I don't use the --machine option specifying my cluster, it will default to some config with max nodes = 1 (generic?). Which is why I steer MPI processes via num-thread. Trying to recover a simulation via simfactory with a new machine file (with num-thread changed) yields an error message: INFO (Carpet): MPI is enabled INFO (Carpet): Carpet is running on 4 processes WARNING level 0 from host nid00392 process 0 in thorn Carpet, file /lustre/tetyda/home/topolski/Cactus/arrangements/Carpet/Carpet/src/SetupGH.cc:148: -> The environment variable CACTUS_NUM_PROCS is set to 96, but there are 4 MPI processes. This may indicate a severe problem with the MPI startup mechanism. What can I do to recover a simulation via simfactory and use a different number of MPI processes? While I'm at it, can I also change parameters such as the number of refinement levels or make new guesses for AHFinderDirect, in case the previously-used parameters did not provide high enough resolution for a successful find? Best regards Konrad Topolski

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Agenda for Thursday's Meeting
by users＠einsteintoolkit.org 12 Jul '21

12 Jul '21

Please update the Wiki with agenda items for Thursday's meeting. Thanks! https://docs.einsteintoolkit.org/et-docs/meeting_agenda --The Maintainers

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coming soon: ET 2021 summer school at UIUC
by Roland Haas 12 Jul '21

12 Jul '21

Hello all, the 2021 ET summer school will start in 2 weeks: July 26th to July 30th 2021 The scientific program is now mostly set and posted to: https://einsteintoolkit.github.io/et2021uiuc/program.html The Einstein Toolkit school is intended to cover the theory behind the Einstein Toolkit's main evolution methods, theory and practise of generating and using initial data for binary neutron as well as hands on exercises on how to run simulations and extend the Einstein Toolkit. Registrations for participation are still accepted, no more lightning talks are accepted at this point. Yours, Roland -- My email is as private as my paper mail. I therefore support encrypting and signing email messages. Get my PGP key from http://pgp.mit.edu .

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Fwd: Midwest Relativity Meeting (First Announcement)
by Helvi Witek 08 Jul '21

08 Jul '21

Dear all, we organize the next Midwest Relativity Meeting at the University of Illinois Urbana-Champaign from 11-13 November 2021. Please find more detailed information in our email below. Best wishes Helvi (on behalf of the organizers) --------------------------------------------- Dr. Helvi Witek Assistant Professor Department of Physics University of Illinois at Urbana-Champaign 247 Loomis Lab 1110 W Green St Urbana, IL 61801 --------------------------------------------- -------- Forwarded Message -------- Subject: Midwest Relativity Meeting (First Announcement) Date: Wed, 7 Jul 2021 12:01:23 -0500 From: Yunes, Nicolas <nyunes(a)illinois.edu> To: Yunes, Nicolas <nyunes(a)illinois.edu> CC: Gammie, Charles Forbes <gammie(a)illinois.edu>, Witek, Helvi <hwitek(a)illinois.edu>, Shapiro, Stuart Louis <slshapir(a)illinois.edu>, Wiltfong, Rebecca <rwiltfon(a)illinois.edu>, Shier, Brandy J <bshier(a)illinois.edu> Dear all, I hope this email finds you well. I am contacting you to let you know about the next Midwest Relativity Meeting, which will be held at the University of Illinois Urbana-Champaign from Thursday November 11th to Saturday November 13th, 2021. We encourage you to attend the meeting in person, but for those of you that cannot attend, we hope to provide a Zoom link. Registration is now open (please click https://midwest-relativity-meeting-2021.physics.illinois.edu/registration and register now!) and it will remain open until November 1st. You will not be able to access the Zoom link or give a talk unless you register. A block of hotel rooms has been separated for you all and a special rate has been negotiated. You can access the hotel registration through this link: https://midwest-relativity-meeting-2021.physics.illinois.edu/travel-lodging…. In order to access this special rate, you must book your hotel before the 20th October, 2021, so go ahead and book now! You can find other information about the meeting in the meeting’s website (https://midwest-relativity-meeting-2021.physics.illinois.edu), including a list of participants and a program which is currently under construction. I hope to see you all at UIUC soon! With kind regards, n. (for the scientific organizing committee) ---------------------------------------------------------------------------------------------------------- | NICOLAS YUNES, | | Founding Director of the | | Illinois Center for Advanced Studies of the Universe, | | Professor of Physics, | | Department of Physics, | | University of Illinois Urbana-Champaign, | | 1110 W Green St, 249 Loomis Laboratory, Tel: (814) 883-2069 | | Urbana, IL 61801 Email: nyunes(a)illinois.edu | ----------------------------------------------------------------------------------------------------------

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Meeting minutes for 2021-07-08
by Leonardo Rosa Werneck 08 Jul '21

08 Jul '21

Chair: Peter Minutes: Leo Present: David, Leo, Miguel, Peter, Roland, Yosef, Zach * Any SpEC updates? No, Roland will send an email. * Any updates on the status of LORENE? Not from anyone in the call. Roland will email Josh about this. * Summer school updates? The program is ready. You can find it on the ETK summer school site (https://einsteintoolkit.github.io/et2021uiuc/). All invited speakers have been contacted. There is still a hole in the schedule which the organizers are currently trying to fill. * David: is there any plans on having a hardware expert for the ETK? No, there are those who are able to help, but not someone dedicated to only doing that. * David: what exactly is the configuration script doing? Difficult to answer, because the entire process is scripted and involves a decision tree. But in a nutshell, a few Perl scripts are called and then make is invoked. * Next ET release: need to find a new release manager. * Unanswered questions in the mailing list: ** http://lists.einsteintoolkit.org/pipermail/users/2021-July/008056.html Roland: Likely the answer to the question is simply that there are reflections happening at the refinement boundaries. Particularly the fact that the constraint violations appear to increase towards the corner of the AMR grids is a good indicator that this is being caused by spurious reflections and interpolation errors. It is possible to mitigate these effects by tweaking some of the parameters. Zach: Very hard to answer and reproduce without having the user's parameter file. It could be an issue with the con2prim in the hydro code, in which e.g. a fluid velocity is coupled to one of the CCZ4 modes and leads to these large errors. Also, why use CCZ4 here? Has BSSN already been tested? ** http://lists.einsteintoolkit.org/pipermail/users/2021-July/008060.html Roland: The fact that PPM and WENO display different behavior in the maximum density over time is not too surprising since the two are quite different. However, the fact that WENO and WENO-Z also display large differences is a bit strange, as the latter is just a slight modification of the former with a few extra things added. Zach: I don't really know what to make of the plots. It may be a problem with the WENO implementation in GRHydro. Would reply to the user: could you please simplify the test a bit? Looking at a BNS is too difficult a test to diagnose these issue, so it would be better to look at convergence tests for a single NS. Roland: Also suspects that the user is using the MHD option in GRHydro but with zero magnetic fields. Zach: Again, it would be easier for us to understand what the user is doing if we had access to their parameter file. Another test that could be performed would be to start with a single NS and then place a refinement level *inside* the star. All the refinement boundary issues should be greatly amplified, but the system should still be stable. Next week's chair: Roland Next week's minutes: Bill

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Workshop on Binary Neutron Stars Next Week (July 12-16)
by Yosef Zlochower 08 Jul '21

08 Jul '21

Hi, Our Theory and Computational Astrophysics Network (TCAN) is hosting an international workshop to discuss the science, observations and simulations of binary neutron stars and black hole - neutron star mergers. The meeting will be held virtually over zoom. The dates will be July 12--16; all talk sessions will be in the morning, US Eastern time. The afternoons will be dedicated to open format discussions. You can view our full schedule here: https://compact-binaries.org/node/2856 <https://compact-binaries.org/node/2856> The topics for the talks on day 1 will focus on reviewing the status of the merger simulations for both BNS and BH/NS binaries. On day 2, talks will be dedicated to nuclear physics, equation of state, nucleosynthesis and post merger simulations. On day 3 (July 14) , the topics will range from particle transport in fluid dynamics, radiation transport and kilonovae. Finally, day 4 we will be dedicated to magnetic field amplification and topology, and jet launching. If you would like to attend, please register by sending me (yosef(a)astro.rit.edu) an email by Sunday 5pm EDT. There is no fee associated with attending.

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Users July 2021