Users February 2021

users@lists.einsteintoolkit.org

14 participants
27 discussions

Einstein Toolkit Meeting Reminder
by users＠einsteintoolkit.org 17 Feb '21

17 Feb '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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Agenda for Thursday's Meeting
by users＠einsteintoolkit.org 15 Feb '21

15 Feb '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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trapping SEGFAULT in CarpetLib's backtrace routines
by Roland Haas 11 Feb '21

11 Feb '21

Hello all, I noticed that the routine request_backtrace in CarpetLib/src/backtrace.cc only sets signal handlers for some of the signals, namely: void request_backtraces() { signal(SIGQUIT, signal_handler); signal(SIGILL, signal_handler); signal(SIGABRT, signal_handler); signal(SIGFPE, signal_handler); signal(SIGBUS, signal_handler); } which has the unfortunate side effect that in a test run of mine on Stampede2 (2020_05 option lists, Intel MPI stack and compiler) no backtrace was generated when I triggered a SEGFAULT. The only indication for a SEGFAULT was the error number (11) reported by MPI. Obviously adding signal(SIGSEGV, signal_handler); is trivial and it does indeed give a me a backtrace. Given the simplicity I am wondering if there was a reason whey SIGSEGV is not trapped by CarpetLib? 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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Science Gateway for the ET
by Steven Brandt 11 Feb '21

11 Feb '21

In our recent proposal, we wrote: <quote>In the future, we plan to add a portal or ``Science Gateway'' to our online teaching tools. This will allow students to become familiar with what the Toolkit does and how to use it before understanding how to build and develop it. It will also allow researchers who are not interested in the mechanics of computational science to make use of the toolkit. The use of Science Gateways on XSEDE resources is on the rise, increasing by a factor of five during the years 2011-2017~\cite{simakov2018workload}, which indicates this to be an important trend in computational research.</quote> I am looking for suggestions about how to make this idea more concrete. In principle, we could have a machine setup with a pre-compiled ETK and a gui to edit select fields of a set of well-chosen parfiles. Does this sound like a reasonable approach? Long term, I had a dream to have a system where students could construct thorns for simple PDE from equations using infrastructure like what Zach et. al. are building now. --Steve

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Meeting Minutes 2021-02-11
by Gabella, William E 11 Feb '21

11 Feb '21

Present: Bill G, Peter D, Ken S, Miguel G, Miguel Z, Yosef Z, Zach E, Karim S, Atul K, Steve B, Roland H, Maria BH Chair: Roland, Minutes: Bill * Any other business or questions? None. [See below at the end of the meeting.] * SPEC benchmark contribution [https://bitbucket.org/einsteintoolkit/tickets/issues/2470 task] [RH, SB] Roland, Steve and Roland are working on. CCZ4 code will be submitted, okay with Spec who want different characteristics than last time. This is 8th order finite difference. Had to set it up with a plain make file---generate source file and Cactus bindings. Done soon-ish. Stripped down version of ETK repo cannot be generally shared, Steve and Roland have it. Someone added OpenACC versions of the kernels, so some work has been done. Steve, why we want a benchmark that does not compute zero---the OpenACC benchmark was very, very fast and result was zero. Should be a result that can be checked. OB, none * release planning [RH] https://docs.einsteintoolkit.org/et-docs/Release_Process https://docs.einsteintoolkit.org/et-docs/Release_Details Zach, Next release is late May, tentatively. Need test runners for the testsuites on supported machines. Roland ran them with scripting on Simfactory last time(s). Originally we farmed out the testsuites to people to test a couple of machines, on the clusters they are familiar with (from when Frank L was managing things). Clusters are becoming more difficult to login, two-factor etc, so maybe needs more individual attention. No action taken. Gallery examples volunteers: Steve, Binary Black Hole GW150914. Did not finish with Visit, other plots, some surface plot problem. Roland, bug in quasi-local measures (fixed 2-3 weeks ago) keeping the VTK files from being made. Use with Gabriele's new Kuibit package, instead of Visit: https://sbozzolo.github.io/kuibit/ Need to set OutVTK to not be zero. Miguel G, Poisson Equation Bill G, Multi-Patch Scalar Wave Equation Peter D, Single, stable (TOV) neutron star Atul K, Binary Neutron Star Zach, Possible new thorns from his group, MaxwellVacuum and MaxwellVacuumID (initial data). Also POWER Maria will review. Roland, has to clean up his version and move it to the Master branch and it will be ready for review. Steve, SimFactory Python 3 (upgrade). Roland's survey about needs/wants in SimFactory, ~20-30 responses. Will try to trim down the SimFactory functionality and that will play into compatibility with Python 3. Would like to build a SimFactory testsuite also. SimFactory in Jenkins ( https://www.jenkins.io/ ) is not tested---setup-silent build is tested, as is submit --testsuite option. Also the Python 3, "set language" problem, or locale problem, utf-8 and ascii, may or may not be a problem (big discussion between Roland and Steve). Updates to CondaPrim, SelfForce1D, and Canuda. Roland, really every change needs review, but for large changes we do the formal review. CondaPrim was from U of Arizona, and IllinoisGRMHD and we have not heard from them recently, so not likely to be ready. Canuda, Miguel Z, adds scalar field thorn, so more than an update, an actual new thorn. Helvi was responsible for it. Miguel, thorn is ready and I have been using it for years. We have internal cross-checked the thorn, believe it is stable, but has not gone through review process for ETK. Helvi is responsible for that. Roland, thought she might be late submitting request because January was very busy. Miguel Z will ask her about the status. Selfforce1D, Peter D, new implementation of equations for gravitational perturbation. So probably major, and will need a review. Might be ready by March 1st. Zach, deadline for officially proposing new items is March 1st. Want reviewers for the above. * ET-US 2021 workshop planning [RH] Need to get started on it, Roland wanted it at UIUC while hosting the Mid-West Relativity Meeting. With Covid, likely still virtual, so it could be anywhere for the host. Want people involved to organize the workshop. People from last committee, setup program, and school schedule. Question, both school and workshop? Seemed to be a consensus for that If virtual, maybe 1/2 day program and twice as long, two weeks long, one week for school and other for worksh itop. When? Maybe after Mid-West Relativity meeting...usually in the Fall---last year's was in October. Roland will check on LIGO meetings, etc, and put out a survey for which weeks are good. Some thoughts that summer would be good too. Also ideas for Program Items please mention them here and mailing list. https://sites.google.com/nd.edu/mwrm-2020/meetings https://sites.google.com/nd.edu/mwrm-2020/ was 22 October 2020 at Notre Dame. * [https://www.einsteintoolkit.org/tools/unanswered.php unanswered question on mailing list] / Script for Unanswered is a bit problematic, so not all are real. The real is "CarpetMask and SphericalSurface (Gabriele Bozzola)" . Steve will take a look and respond. * [https://bitbucket.org/einsteintoolkit/tickets/issues?status=open&status=new… open tickets sorted by update time] / * [https://bitbucket.org/einsteintoolkit/tickets/issues?status=new&status=open… tickets ready for review] #2386 CCTK_LOOP3_INT and friends broken..., Miguel Z will have a look at the bug fix and pull request. He says fix works for him. https://bitbucket.org/einsteintoolkit/tickets/issues/2386/cctk_loop3_int-an… * Any other business? Steve, Funded proposal had a scientific gateway ifor the ETK, could be for teaching purposes, could be other. Web portal? Chat bot? Steve wants to know what would we find useful for teaching or other. Bring up next week. * Chairs and Minute takers Feb 18th Chair Peter D, Minutes Maria BH Feb 25th Chair Steve B, Minutes Atul K -- ============================== William Gabella Research Assistant Professor Department of Physics and Astronomy Nashville, TN USA (o) 615-343-2713

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Lines between black hole surfaces in Visit
by Chris Stevens 11 Feb '21

11 Feb '21

Hi everyone, I am new to visualizing output from a binary black hole merger, and I am currently experimenting with Visit. I have imported the surface .vtk objects for the two black holes. When I add meshes for them they appear correctly but are connected, rather than two separate entities. If this doesn't make sense I will attach a picture in a future email. Is there a way to get rid of this in Visit? Thanks, Chris -- Dr Chris Stevens Postdoctoral Fellow Rm 310A Department of Mathematics and Statistics University of Otago Ph: +64 3 479 4567 http://www.chrisdoesmaths.com http://gravity.otago.ac.nz

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Einstein Toolkit Meeting Reminder
by users＠einsteintoolkit.org 10 Feb '21

10 Feb '21

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Postdoctoral position in numerical relativity at RIT
by Yosef Zlochower 10 Feb '21

10 Feb '21

As part of several NASA and NSF collaborative projects, RIT’s Center for Computational Relativity and Gravitation (CCRG) is currently seeking to fill one or two postdoctoral research positions with highly qualified individuals interested in pursuing research in the fields of numerical relativity, theoretical and computational astrophysics, with an emphasis on general relativistic magneto-hydrodynamics simulations. We are particularly interested in developing new high-performance algorithms for relativistic magneto-hydrodynamics simulations of binary neutron star coalescences from prior to merger through to the formation of disks and/or collapse of the merged remnant, the production of jets, and launching of outflows. The group is involved in several large collaborations, including the LIGO Scientific Collaboration (LSC), The Einstein Toolkit Consortium (einsteintoolkit.org) and a NASA Theoretical and Computational Astrophysics Network (TCAN) (compact-binaries.org). CCRG researchers have access to several computing cluster facilities at national computing centers such as XSEDE and the TACC’s Frontera Supercomputer, as well as a dedicated over 3500-cores cluster and large storage pool hosted at the Center. Applications should consist of a cover letter, a brief statement of research interests, a curriculum vitae including publication list, and at least three letters of recommendation. All materials should be sent electronically as soon as possible to: qxysma[AT]rit.edu with a copy to ccrg-postdoc[AT]ccrg.rit.edu. More information about the CCRG is available at http://ccrg.rit.edu/. And about Rochester at http://en.wikipedia.org/wiki/Rochester,_New_York Application reviews will be begin immediately and continue until the position is filled. Starting dates, duration and a competitive salary are negotiable.

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CarpetX tutorial during ET call
by Roland Haas 09 Feb '21

09 Feb '21

Hello all, due to CarpetX development having reached a stage where it is ready for early users to test it with their science codes, Erik agreed to give a short CarpetX tutorial in one of the ET calls. The initially proposed date of 2021-02-18 unfortunately conflicts with other conferences. Please use: https://doodle.com/poll/r4snxqpn6es3kicy?utm_source=poll&utm_medium=link to indicate times you would be interested and available for such a 1 hr long tutorial. Deadline to respond is end of this week (Saturday February 6th) to leave time for preparation. 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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Agenda for Thursday's Meeting
by users＠einsteintoolkit.org 08 Feb '21

08 Feb '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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Users February 2021