Users March 2017

users@lists.einsteintoolkit.org

18 participants
25 discussions

Re: [Users] [ET Trac] [Einstein Toolkit] #1326: running loopcontrol on strange number of threads fails
by Erik Schnetter 11 Apr '19

11 Apr '19

Do you have a backtrace? -erik On Sunday, March 22, 2015, Einstein Toolkit < trac-noreply(a)einsteintoolkit.org> wrote: > #1326: running loopcontrol on strange number of threads fails > ------------------------------------+--------------------------------------- > Reporter: rhaas | Owner: > Type: defect | Status: new > Priority: minor | Milestone: > Component: EinsteinToolkit thorn | Version: > Resolution: | Keywords: LoopControl > ------------------------------------+--------------------------------------- > > Comment (by rhaas): > > This still happens even with current (Sun Mar 22 18:46:21 CET 2015) trunk, > though failure looks a bit different now: > {{{ > actus_sim: > /data/rhaas/postdoc/gr/ET_trunk/configs/sim/build/LoopControl/loopcontrol.cc:312: > T {anonymous}::divexact(T, T) [with T = int]: Assertion `i % j == 0' > failed > }}} > > -- > Ticket URL: <https://trac.einsteintoolkit.org/ticket/1326#comment:1> > Einstein Toolkit <http://einsteintoolkit.org> > The Einstein Toolkit > _______________________________________________ > Trac mailing list > Trac(a)einsteintoolkit.org > http://lists.einsteintoolkit.org/mailman/listinfo/trac > -- Erik Schnetter <schnetter(a)cct.lsu.edu> http://www.perimeterinstitute.ca/personal/eschnetter/

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GW150914 example, noisy Psi4 waveforms
by Christian D. Ott 18 Jun '17

18 Jun '17

Hi All, I have been experimenting with the GW150914 par file (Thanks for putting it together!), which uses Llama multipatch (MP) with McLachlan (ML) and, of course, Carpet AMR in the interior Cartesian patch, tracking the punctures. I'm noticing three things when looking at Psi4 l2,m2 waveforms (and this is largely independent of extraction radius): (1) The waveforms have high-frequency wiggles that similar pure-AMR simulations do not show. I don't have a pure AMR simulation for GW150914, but am comparing with an 8-orbit, equal mass, non-spinnning case. I can run GW150914 with pure AMR if need be. (2) The high-frequency wiggles get *worse* if I decrease the finite differencing order from 8th to 4th order. (3) This appears to be a wave amplitude-dependent 'feature', since the wiggles are much less pronounced once the waves reach higher amplitudes. I'm attaching two gnuplot screenshots: fig1.png shows the first ~800 M of Psi4 l2,m2 real at r=136 M with the stock par file and with a modified par file for 4th order. fig2.png is a zoom-in. I'm also attaching the par file that I'm using for the 4th-order run. Now my questions: Does anybody have an idea where the high-f noise is coming from and why it's getting worth for lower FD order? Any suggestions on how to mitigate it? Thanks! - Christian

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Einstein Toolkit Meeting Reminder
by Frank Loeffler 13 Apr '17

13 Apr '17

Please consider joining the weekly Einstein Toolkit phone call at 9:30 am US central time on Mondays. As usual, you can find instructions how to join on the following web site: http://einsteintoolkit.org/community/support/ We use a Google hangout, with an URL announced on this list about 15 minutes before the meeting. ***** Please note that most of Europe (and maybe also other parts of the world) changed to Summer time this weekend, which means for those, the meeting time is now the regular time again, after being offset for the last two weeks. ***** Frank Löffler

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ET on KNL.
by Eloisa Bentivegna 03 Apr '17

03 Apr '17

Dear all, I was wondering if anybody is using the ET on the Knights Landing architecture, and what sort of performance one could expect to get. Admittedly without much optimization, I am measuring a performance per core which is almost two orders of magnitude smaller than that of a Broadwell Xeon. Does this sound wildly off? Eloisa

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Reduction in slices?
by Francisco Guzman 31 Mar '17

31 Mar '17

Dear all, Assume I have a thorn mounted on Carpet, completely unrelated to any GR thorn (say my_wavetoy) . Is there a way to estimate the integral of a grid function on every slice of z=constant? This reminds me the outflow thorn that is capable of estimating the integral of fluxes (grid functions) across a spherical surface. I wonder whether there is something similar to integrate a flux (a given grid function of my choice) across z=constant planes: - perhaps a reduction operator from Carpet - a similar thorn to outflow Thanks in advance, Francisco

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Response to NSF Dear Colleague Letter
by Frank Loeffler 30 Mar '17

30 Mar '17

Dear Einstein Toolkit users and developers, At the NSF SI2 PI meeting this year, a few of the PIs got together to respond to the NSF 17-031 Dear Colleague Letter: Request for Information on Future Needs for Advanced Cyberinfrastructure to Support Science and Engineering Research (NSF CI 2030) [1]. The response with the title "Research Software Training Initiative: Identifying and addressing challenges in scientific software development" can be found here: https://docs.google.com/document/d/1M0RcbsjBRQIC_eO16SMYhnAM4TgwPM866DMWqR7… In order to give this response more weight, we will include a list of researchers that agree with what has been written, in addition to the original authors. For this: *** We need your help! *** Please read the response, and if you agree with the response, are happy to help and to be included in the list, please add your information toResponse to NSF Dear Colleage Letter https://docs.google.com/spreadsheets/d/1YciB5Z8hMx7cePQkrCrSX4ZM41aPTPiMjFr… The deadline for responses is April 5th, but: in order to ensure a timely response and to leave some time for final editing of the web form data, I have set the deadline to be added to the list to Tue, April 4th (Tuesday next week) You are encouraged to forward this information to any researcher you think might be interested, but for the sake of spam avoidance, please try to keep it from being too public. If you have trouble with the Google spreadsheet, feel free to send me an email instead. Thank you very much already in advance, Frank Löffler [1] https://www.nsf.gov/pubs/2017/nsf17031/nsf17031.jsp

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ET on KNL
by Steven R. Brandt 29 Mar '17

29 Mar '17

Dumb question. Where can I find a cfg file for KNL? The one that was here is gone: https://docs.einsteintoolkit.org/et-docs/2017_MHD_Workshop --Steve

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Excision with McLachlan
by Miguel Zilhão 28 Mar '17

28 Mar '17

hi all, i was wondering whether one could straightforwardly use the ET to perform black hole evolutions using excision instead of punctures. specifically, i had in mind a collapsing configuration where i'd like to excise the inner domain once a black hole horizon is formed... is this possible? i had a look around and noticed the LegoExcision thorn, but i'm not sure whether it's actively maintained, nor whether it can interface with McLachlan... thanks, Miguel

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Assorted Parameter File Questions
by Gwyneth Allwright 23 Mar '17

23 Mar '17

Hi All, I have a bunch of overdue questions about parameter files that I've been meaning to ask. I'd be really grateful for any help. Also, if resources that address these questions already exist somewhere, please let me know! 1. I've seen ML_Ham and ML_mom from both ML_ADMConstraints and ML_BSSN requested as output in parameter files. Is there a difference? 2. IOScalar, IOBasic and IOASCII all seem to be able to produce 0D output, yet I've often seen all three used in the same parameter file. Is there a reason for this? 3. The following lines are from the example BBH parameter file ( https://einsteintoolkit.org/gallery/bbh/GW150914.rpar): # Drop order instead of using upwinded stencils, only for advection derivatives SummationByParts::sbp_upwind_deriv = no SummationByParts::sbp_1st_deriv = yes SummationByParts::sbp_2nd_deriv = no I don't have a very good understanding of what's being done here, but it seems as if we don't require the upwind and second derivative operators to satisfy summation by parts, so they're implemented by a different thorn? (Perhaps instead by GlobalDerivative?) 4. With the ADMMass thorn, one has to exclude the interiors of the compact objects. The documentation mentions using OutsideMask for this, but I can't find such a thorn. I also haven't been able to find a parameter file that uses ADMMass, but I've seen SpaceMask and CarpetMask used for other purposes, as well as the parameter: AHFinderDirect::set_mask_for_individual_horizon. I'm curious about how these different masking approaches work, and which is preferable. 5. Does calculating the ADM mass using QLM also require excluding the interiors of the objects? 6. For stable evolution on Cartesian grids, we need to halve the CFL factor on the outermost grid by setting Carpet::time_refinement_factors [1,1,...]. However, this isn't done for the example BNS parameter file ( https://einsteintoolkit.org/gallery/bns/nsnstohmns.par). Is it specific to BBHs? Sorry for the many questions! If it would be easier to address them during one of the calls, I'll probably be able to make next Monday... Gwyneth

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IOHDF5 Error
by Gwyneth Allwright 22 Mar '17

22 Mar '17

Hi All, One of my simulations recently aborted with the following error: cactus_ET: /opt/exp_soft/EinsteinToolkit/Cactus/arrangements/Carpet/CarpetLib/src/bboxset2.hh:261: bboxset2::bboxset<T, D> bboxset2::bboxset<T, D>::binary_operator(const F&, const bboxset2::bboxset<T, D>&) const [with F = bboxset2::bboxset<T, D>::operator&(const bboxset2::bboxset<T, D>&) const [with T = int; int D = 3]::<lambda(const bboxset1&, const bboxset1&)>; T = int; int D = 3]: Assertion `all(stride == other.stride)' failed. This was when running on an HPC cluster. On my laptop, it works fine and I don't get this error. However, commenting out the following section in my parameter file resulted in a successful HPC run: Activethorns = "CarpetIOHDF5" IOHDF5::one_file_per_group = "yes" IOHDF5::out0D_every = 128 IOHDF5::out0D_vars = " WEYLSCAL4::Psi4r WEYLSCAL4::Psi4i PunctureTracker::pt_loc " This is the only HDF5 output I'm requesting. Am I doing something silly here? If it would help, I'd be happy to open a ticket and attach the whole parameter file, backtrace etc. Gwyneth

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Users March 2017