Users April 2017

users@lists.einsteintoolkit.org

19 participants
25 discussions

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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units
by Francisco Guzman 13 Apr '17

13 Apr '17

Hi all, Could you guys please point me to the reference where I can see how units are defined for a binary black hole simulation? (Or possibly simply answer): I just want to know what the units of space and time (M) are. What is M? is it the ADM mass at initial time? the addition of the two black hole masses?... or so... I apologize in advance in case my question is terribly dummy. Thanks, Francisco

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Einstein Toolkit Meeting Reminder
by Frank Loeffler 11 Apr '17

11 Apr '17

Hi 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. Frank Löffler

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compile instructions for funhpc
by Roland Haas 11 Apr '17

11 Apr '17

Hello Erik, do you have up to date (ie post cmake) instruction on how to compile funhpc on a linux machine? 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://keys.gnupg.net.

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machine files for KNL
by Khamesra, Bhavesh 10 Apr '17

10 Apr '17

Hi everyone, I wanted to run a few simulations on Stampede's KNL nodes. I tried to write the machine files but was facing some issues. Does einstein toolkit have machine files for Stampede 2 or Stampede's updated KNL platform? If yes, which one? And if not, are there any machine files for KNL architecture which I could use as reference? Thank You ............................. Bhavesh Khamesra Graduate Student Centre of Relativistic Astrophysics Georgia Institute of Technology

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IOScalar Reductions
by Gwyneth Allwright 07 Apr '17

07 Apr '17

Hi All, I'm currently trying to make sense of the 0D output files for the momentum and Hamiltonian constraint errors (from ML_ADMConstraints and ML_BSSN). When using IOScalar, many files are produced, apparently using various norms and reductions: *.average, *.count, *.d, *.maximum, *.minimum, *.norm1, *.norm2, *.norm_inf, *.sum (as well as the above with an "i" in front of each descriptor, e.g. *.iaverage). I'd naively guess that iaverage, isum etc. are reductions using imaginary components, while the others are with real components, but have no clue whether this is correct (I'm not sure whether these errors can run over the imaginaries). Do norm1, norm2 and norm_inf refer to the L-1, L-2 and L-infinity norms? I'm unsure of what *.count represents -- perhaps the number of grid points over which the reductions are calculated? Are the values used to calculate the reductions taken from different refinement levels? What does *.d represent? For 1D IOASCII output, the headings look something like: # refinement level 1 multigrid level 0 map 0 component 26 # column format: 1:it 2:tl 3:rl 4:c 5:ml 6:ix 7:iy 8:iz 9:time 10:x 11:y 12:z 13:data I'm unsure of what many of these mean: "multigrid level", "map" and "component" in the first row; 3 to 8 in the second row. I'm especially curious about what the components are, because I'm only seeing data for a small number of components. Thanks very much for the help! Gwyneth

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Re: [Users] Install ET on OSG
by Ashiqul Islam Dip 05 Apr '17

05 Apr '17

Dear ET Users I have used the recipe described in the "Tutorial for New Users" The error I get when trying to build simfactory: checking whether the C compiler (gcc -g -std=c11 -rdynamic) works... no configure: error: installation or configuration problem: C compiler cannot create executables (see configs/<configname>/config-data/config.log for details). Error reconfiguring sim-config make: *** [sim-config] Error 2 With best regards Ashiqul Islam Dip ---------------------------------------- From: "Ian Hinder" <ian.hinder(a)aei.mpg.de> Sent: Wednesday, April 05, 2017 1:44 PM To: dip(a)communityofphysics.org Subject: Re: [Users] Install ET on OSG On 5 Apr 2017, at 01:19, Ashiqul Islam Dip <dip(a)communityofphysics.org> wrote: Dear Einstein Toolkit User, I was trying to install Einstein Toolkit on Open Science Grid. Their computer runs on Scientific Linux release 6.8 (Carbon). Can anyone tell me how to get ET installed on the system? Every time I get a "sim-config" error, when I try to build the simfactory. Hi, Welcome! Please can you provide more information? - What instructions are you following? - Which step failed? - What was the error message? Without such information, we can't really help you... I don't know if anyone has tried on the OSG before, but Scientific Linux should work (or it should be possible to make it work, if it doesn't work immediately from an existing optionlist). -- Ian Hinder http://members.aei.mpg.de/ianhin

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Install ET on OSG
by Ashiqul Islam Dip 05 Apr '17

05 Apr '17

Dear Einstein Toolkit User, I was trying to install Einstein Toolkit on Open Science Grid. Their computer runs on Scientific Linux release 6.8 (Carbon). Can anyone tell me how to get ET installed on the system? Every time I get a "sim-config" error, when I try to build the simfactory. With best regards Ashiqul Islam Dip Chief Researcher Community of Physics

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Documentation links not working
by Khamesra, Bhavesh 04 Apr '17

04 Apr '17

Hi everyone, I was trying to access the documentation of einstein toolkit but when I click on the link of Users Guide, Thorn Guide or Cactus Reference Manual I get an error page with this message - The requested URL /referencemanual/ReferenceManual.html was not found on this server. Additionally, a 404 Not Found error was encountered while trying to use an ErrorDocument to handle the request. Could someone please look into this? Thanks ............................. Bhavesh Khamesra Graduate Student Centre of Relativistic Astrophysics Georgia Institute of Technology

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New Code Announcement: GiRaFFE
by Zach Etienne 04 Apr '17

04 Apr '17

Dear ET folks, We are pleased to announce the public release of *GiRaFFE*, an open-source General Relativistic Force-Free Electrodynamics (GRFFE) code for dynamical spacetimes. *-= Code Release Paper =-* Our code release paper--including a full description of the GiRaFFE code, a discussion of potential applications of GiRaFFE, and code validation test results--has been uploaded to the arXiv: https://arxiv.org/abs/1704.00599 . *-= Executive Summary =-* GiRaFFE adopts the strategy pioneered by McKinney [1] and modified by Paschalidis and Shapiro [2] to convert a general relativistic magnetohydrodynamic (GRMHD) code into a GRFFE code. In short, GiRaFFE exists as an extensive modification to IllinoisGRMHD [3]. Both GiRaFFE and IllinoisGRMHD leverage the Einstein Toolkit’s highly-scalable infrastructure [4,5] to make possible large-scale simulations of magnetized plasmas in strong, dynamical spacetimes on adaptive-mesh refinement (AMR) grids. As you are aware, IllinoisGRMHD is an open-source rewrite of the Illinois Numerical Relativity Group's GRMHD code. GiRaFFE, on the other hand, is not based on any existing GRFFE code and is designed only to solve the equations of GRFFE in the context of fixed or dynamically-generated spacetimes. GiRaFFE has passed a large suite of GRFFE code validation tests passed by other state-of-the-art GRFFE codes, leading us to conclude that GiRaFFE is now ready for large-scale, state-of-the-art GRFFE simulations in dynamical spacetimes. *-= New Thorns for the Einstein Toolkit =-* All GiRaFFE thorns are listed below. Next to the name of each thorn, we include the number of lines of code to highlight the fact that *GiRaFFE is quite compact and designed to be welcoming to new users*. In addition, the comment-to-line-of-code ratio is very nearly 50%, and the code release paper provides a clean, broad-brush overview of the formalism and algorithms adopted. To become acquainted with any given thorn, first take a look at its README file. ** GiRaFFE (~1,600 lines of code)*: Solves the GRFFE equations in the formalism of Paschalidis & Shapiro [2] using the same reconstruction (PPM) and staggered vector potential methods as IllinoisGRMHD. ** GiRaFFEfood** (~1,300 lines of code)*: Code validation initial data and basic diagnostics. Contains - Five 1D tests in flat spacetime (fast wave, Alfvén wave, degenerate Alfvén wave, "three-wave", FFE breakdown), - One 3D test in flat spacetime (aligned rotator), and - Three 3D tests in curved spacetimes ("Exact Wald" solution, "Magnetospheric Wald" solution, and split monopole). ** ShiftedKerrSchild (~230 lines of code)*: Sets up all 3+1 quantities for a Kerr-Schild spacetime with an arbitrary radial shift, to mitigate effects of extreme spacetime curvature near r_{KS}=0. See Appendix of code release paper for full discussion. ** VolumeIntegrals_slab_Gfood (~310 lines of code)*: Performs volume integrals over arbitrary rectangular prisms as specified in parameter files. ** GiRaFFE_to_HydroBase* & *ID_converter_GiRaFFE (~230 lines of code)*: Acts as a translation layer to convert 3-velocities in HydroBase's Valencia formalism to/from the 3-velocity found in the induction equation (v^i = u^i/u^0; native to GiRaFFE). *-= License =-* To maximize compatibility with existing thorns in ET, all of the aforementioned GiRaFFE thorns are either licensed GPLv2+ or 2-clause BSD (FreeBSD). See LICENSE file in each. *-= Download GiRaFFE! =-* *The collection of thorns comprising GiRaFFE may be downloaded here:* *https://bitbucket.org/zach_etienne/wvuthorns <https://bitbucket.org/zach_etienne/wvuthorns>* Sincerely, The GiRaFFE team -Zach Etienne -Mew-Bing Wan -Maria Babiuc -Sean McWilliams -Ashok Choudhary References: [1] J.C. McKinney. Mon. Not. R. Astron. Soc., 367:1797, 2006. [2] V. Paschalidis and S. L. Shapiro. Phys. Rev. D, 88:104031, 2013. [3] Z. B. Etienne, V. Paschalidis, R. Haas, P. M¨osta, and S. L. Shapiro. Class. Quantum Grav., 32(17):175009, 2015. [4] https://einsteintoolkit.org/ [5] https://carpetcode.org/

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Users April 2017