Users April 2020

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14 participants
24 discussions

Instabilities with Summation by Parts 4th order operator
by Miguel Zilhão 07 May '20

07 May '20

hi all, i've been working on implementing the Summation by Parts (SBP) operators on some evolution codes i have and i was seeing some instabilities when using the 4th order accurate 2nd derivative operator. in order to try to understand the problem better, i've coded a very simple thorn that evolves the wave equation in first-order in time, second-order in space form. i can evolve the system just fine without any problems with the SBP operators of order 2, 6 and 8. with order 4, however, there are instabilities propagating from the boundary that crash the code very early on. has anyone seen something like this before? could there be a bug in the 4th order 2nd derivative SBP operators, or am i doing something wrong? i find it very strange that it only crashes with the 4th order accurate 2nd derivative SBP stencils (the code also seems to run fine with the parameter SummationByParts::sbp_2nd_deriv = no)... i've uploaded this thorn (called IST_WaveToy) here: https://github.com/mzilhao/IST_WaveToy i tried to keep everything as simple as possible. i'm attaching the thornlist used to checkout and compile the code, and in the repository i've also added the parameter files i tried with the different SBP orders (under ./par). any help or comments would be appreciated. thanks, Miguel

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A question about radius in CarpetRegrid2
by ZhiChao Zhao 30 Apr '20

30 Apr '20

Hi All, I am using ET to simulate a BNS merge. I set the radius as(max 7 level): CarpetRegrid2::radius_1[1] = 270.0 CarpetRegrid2::radius_1[2] = 162.0 CarpetRegrid2::radius_1[3] = 94.5 CarpetRegrid2::radius_1[4] = 40.5 CarpetRegrid2::radius_1[5] = 27.0 CarpetRegrid2::radius_1[6] = 13.5 However, when I check the radius of mesh in VisIt(the output h5 file), I found the radius of each level becomes: [ 512, 352, 200, 112, 50, 32, 16] , which is different from what I have written in CarpetRegrid2:: radius_1[index]. Could anyone tell me how the radius transfer from 270.0 to 352? Or give me any document of Carpet? My another parameters are: CoordBase::dx = 6.4 CoordBase::xmax = 512.00 Carpet::ghost_size = 3 Carpet::prolongation_order_space = 5 Thanks a lot! Yours, Zhichao Zhao.

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Meeting Minutes for 2020-04-30
by Steven R. Brandt 30 Apr '20

30 Apr '20

Present: Ian Hinder, Steve, Bill, Roland, Peter, Alois Peter, Helvi, Zhichao Zhao, Yosef, Christopher Evens, Zach, Atul Chair: Helvi Note Taker: Steve Update to cactuscode - Regenerated for the last time (?) - List of issues: https://github.com/EinsteinToolkit/cactuscode.org/issues * Bugs (problems with the conversion) * Enhancements (this probably out of date) * No longer have dynamic comments Zach: Gcc9.3.0 takes a ridiculously long time in MacOS it takes half an hour to compile the 8th order code. Under Linux it takes 30 seconds or so. Ian suggests that the "inline" might be the problem. Also, it could be the architecture. Note the compile is fast with less than 9.3. Zach is able to get it to compile faster by splitting up the routine. Report to GCC maintainers? Release will be pushed back by another week to make it possible for everyone to catch up. PreSync addressing Roland comments. Vector support in Fortran Do Macro changes for Kranc? No. New release test suite results Roland sees nothing unexpected Cory, SuperMUC, Golub show more failures than we'd like (Intel compiler) But no new failures Roland tracks how long it takes to build and how long it takes to run the tests Steve notes that we need parallel tests Bugs: fix adaptive time stepping others are presync related Gallery: Change the representation of the data on the website? Since it's targeting the first LIGO detection, could it be somehow compared to what LIGO saw? Add a link to the LIGO data? Some problems comparing with LIGO data. Poisson example--had some problems running and comparing numbers. How was the plot made? Visit session file in the ticket. there are scripts in https://bitbucket.org/einsteintoolkit/www/src/master/gallery/bbh/ for generating some of the plots (you need mathematica and simulationtools) Summation by parts question, Peter was supposed to update

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Einstein Toolkit Meeting Reminder
by users＠einsteintoolkit.org 29 Apr '20

29 Apr '20

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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kesnar spacetime graphs.
by Nisa Amir 29 Apr '20

29 Apr '20

Hello, Hope all of you are doing well. I am trying to replicate some examples given in par directory of the Cactus for practice. I have run the parameter file kasner.par, have obtained the results but my graph is not correct according to the paper arXiv-1111.3344. I am attaching the parameter file which I have run, the resulting .asc file and the graph I have obtained. Kindly, anyone guide me what mistake I am making. Thanks

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Agenda for Thursday's Meeting
by users＠einsteintoolkit.org 27 Apr '20

27 Apr '20

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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Error in exe/cactus_sim
by Rishank Diwan 27 Apr '20

27 Apr '20

Dear Sir/Madam I am trying to compile a Cactus executable on my laptop, which has an ubuntu-based operating system(Ubuntu 18.04). I am using the latest version i.e; ET_2019_10. I am using simfactory and following the Simulation Factory Advanced Tutorial. For building, I am using generic configuration files which are also the default files. Here are the steps I am using: simfactory/bin/sim setup ./simfactory/bin/sim build -j2 --thornlist ../einsteintoolkit.th Compilation produces an executable, but when I go for running the example file using the command, exe/cactus_sim I get the following error. "" Fatal error in PMPI_Comm_rank: Invalid communicator, error stack: PMPI_Comm_rank(110): MPI_Comm_rank(comm=0x8202540, rank=0x7ffcee11d818) failed PMPI_Comm_rank(68).: Invalid communicator [unset]: write_line error; fd=-1 buf=:cmd=abort exitcode=805918213 : system msg for write_line failure : Bad file descriptor "" I am not able to find any relevant solution on the internet. Can you please help me find in the solution. Yours Sincerely, Rishank Diwan Pre-final Year Undergraduate Student Department of Physics Indian Institute of Technology, Kharagpur

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Meeting Minutes 2020-04-23
by Bill Gabella 23 Apr '20

23 Apr '20

Present: Steve B, Bill G, Roland H, Atul K, Peter D, Alois Peter S, Zhichao Z, Zach E., Christopher E., Maria BH, Yosef Z, Erik S Chair: Steve Minutes: Bill Steve does have a no cost extension, so the LSU Fall workshop could be put off until the next year. Asked Ian Hinder about moving Cactus code to Github. Is anything else on the SVN server? RH, Some tools only exist there which could be moved. Check if the mailing list is there. GW analysis code only exists there at this point. SB, We want to retire that server. * update on potential codes to be included in next release, from minutes [RH] o BaikalETK (Zach, Helvi) Zach says he should be sending email to Helvi. *14 days until feature freeze.* o PreSync (Steve, Roland) Roland and Steve have been communicating. Issues to be resolved and working on them. RH, could be a struggle to get everything in. * *feature freeze in **14**days*, https://www.timeanddate.com/countdown/to?iso=20200507T09&p0=3704&msg=Featur… timeline [RH] https://docs.einsteintoolkit.org/et-docs/Release_Details#Schedule_for_ET_20… * Release testsuite results [RH] http://einsteintoolkit.org/testsuite_results/index.php RH no updates. More important thing is to put on the website the fails of the testing, script needs updating and should take 1-2 hours to fix up. Best if you can see what changed easily. Script is in the testsuite results, and link that says all the results are stored in here. In there a Perl script is in the toplevel directory...also a CLI so that you can try this out (some details below). SB needs to run the Linux tests. o bugs of severity major or worse https://bitbucket.org/einsteintoolkit/tickets/issues?kind=bug&priority=majo… #2370:Wrong MoL surprises Steve, he has used it. RH, was always incorrect in Schedule.ccl so the order could be random. Likely changed in the last years, maybe when MoL changed, counting variables(?). #2368 Summation by parts, SB is anything going to happen? Peter will look at it today or tomorrow. #2336 Cactus version number in Makefile, Roland will fix soon. o trivial or minor bugs tagged for the next release https://bitbucket.org/einsteintoolkit/tickets/issues?kind=bug&priority=mino… o other open tickets flagged for the next release https://bitbucket.org/einsteintoolkit/tickets/issues?kind=proposal&kind=enh… * gallery testing: tasks https://bitbucket.org/einsteintoolkit/tickets/issues?kind=task&milestone=ET… See the note above about fixing script to add results to the web page. * volunteers needed, please volunteer (someone) [RH] Have volunteers for everything. o TOV: Brock Brendal (UIUC) o BNS: Shawn Rosofsky (UIUC) o BBH: Alois Peter Schaffarczyk (Kiel) << Atul K will help with post-processing, see below. o Poisson: Bill Gabella (Vanderbilt) o Multipatch scalar wave: Beyhan Karakaş (Ege University) unanswered question on mailing list https://www.einsteintoolkit.org/tools/unanswered.php Apr 9: Should put in a response on the "Instabilities with Summation..." Peter reminds us we discussed it last week. open tickets sorted by update time https://bitbucket.org/einsteintoolkit/tickets/issues?status=open&status=new… tickets ready for review https://bitbucket.org/einsteintoolkit/tickets/issues?status=new&status=open… All other business? Atul K. asked if he could help with gallery testing. Atul will work with Alois Peter S. on the BBH. Peter says the run has been done, on two machines, and starts the post-processing and there help would be good. They will coordinate. Chairs and minute taker for future meetings: 1st week May, 7 May 2020, Roland chair, Bill minutes 2nd week May, 14 May 2020, Zach chair, Maria minutes Zach tried to compile ETK on cell phone. First issue was a dumb thing, easy to fix. config.guess file is "12 years old" since last update. Gnu updates more frequently, could not recognize the ARM cpu. SB says make a ticket and a pull request. Extension of the existing script from the GNU folks. Steve has compiled on a Raspberry Pi...Erik recalls updating 8 years ago, the config.guess for the RPi. From above, Roland put in the chat his running the *Perl update script *on the command line: perl ./compare_results.pl ET_2019_03_v0 master results/bluewaters__{1_8,2_8}.log results/comet__{1_24,2_12}.log results/golub__1_10.log:results/golub__1_12.log results/golub__2_10.log:results/golub__2_12.log results/stampede2*.log results/osx-macports__*.log And a colon between items indicates a filename change between the two releases, as in the two Golub entries. -- ===================================== William Gabella Research Assistant Professor Department of Physics and Astronomy Vanderbilt University Nashville, TN USA b.gabella(a)vanderbilt.edu (o) 615-343-2713

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Einstein Toolkit Meeting Reminder
by users＠einsteintoolkit.org 22 Apr '20

22 Apr '20

1 0

Agenda for Thursday's Meeting
by users＠einsteintoolkit.org 20 Apr '20

20 Apr '20

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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Users April 2020