Users March 2013

users@lists.einsteintoolkit.org

8 participants
19 discussions

Example: Using complex numbers in C
by Erik Schnetter 12 Mar '13

12 Mar '13

[I am posting this example in response to a request I received in private.] This is how you can use complex numbers from C. This code assumes that you have declared CCTK_COMPLEX grid functions u, v, w. (I didn't actually try to compile this example, but the overall structure should be fine.) #include <cctk.h> #include <cctk_Arguments.h> #include <complex.h> #include <math.h> void do_some_complex_calculations(CCTK_ARGUMENTS) { DECLARE_CCTK_ARGUMENTS; #pragma omp parallel for for (int k=0; k<cctk_lsh[2]; ++k) { for (int j=0; j<cctk_lsh[1]; ++j) { for (int i=0; i<cctk_lsh[0]; ++i) { const int idx = CCTK_GFINDEX3D(cctkGH, i,j,k); CCTK_COMPLEX tmp = 2.0 + 3.0 * I; u[idx] = conj(tmp) * v[idx] + 2.0 * cabs(w[idx]); u[idx] = cexp(u[idx]) - creal(tmp) + cimag(tmp); } } } } -erik -- Erik Schnetter <schnetter(a)cct.lsu.edu> http://www.perimeterinstitute.ca/personal/eschnetter/

1 0

parameter file format
by Steven R. Brandt 12 Mar '13

12 Mar '13

I added this wiki page to discuss the Piraha syntax issues. Please contribute. https://docs.einsteintoolkit.org/et-docs/Piraha_Parser_Discussion Cheers, Steve

1 0

meeting minutes
by Roland Haas 11 Mar '13

11 Mar '13

Present were: Frank, Roland, Ian, Steve, Peter, Yosef, Eloisa, Erik Parameter file parser * add two modes for parameter file parsing - one fully backwards compatible - one using newer syntax and providing better error messages * create wiki with new syntax and features as well as status of implementation - want special notation for multi-line strings a la python """ - make sure Cactus expression evaluator in flesh and parfile expression evaluator support same math syntax Corrupt output files: * for now, rename files that are being written to, the way that checkpoint files are renamed * simfactory defaults and parfiles to revert to have checkpoints in each output folder * add option to Cactus flesh to indicate termination due to wallclock time. Only in that case should simfactory continue the runs * specify termination reason via either an argument to the call CCTK_TerminateNext and/or via a steerable parameter the way that the cactus terminate_next parameter. Should this be an integer or a string/keyword? Production executables with hard-coded parameter values: * Erik tested how much speedup ones gains by replacing the dynamic parameters in ML by hard-coded ones (on the compiler level). He found a speedup of ~2%. * desire to have such functionality for production runs * currently Erik used hand-coded preprocessor defines * instead we would like a file specifying the hard-coded parameters, ideally as a parameter file fragment incl the option of hard-coding it to the default value * this requires a stand-alone parameter parser and evaluator Yours, Roland

2 2

Einstein Toolkit Meeting Reminder
by Frank Loeffler 10 Mar '13

10 Mar '13

2 2

bug in Dissipation thorn?
by Kentaro Takami 07 Mar '13

07 Mar '13

Dear all, I encountered the problem in which the simulation result is randomly different at each run( of course I used same executable, par file, HPC and so on.). Finally I'm doubting the origin of the problem is "CactusNumerical/Dissipation", because when I don't activate this thorn, the problem can be disappeared. In this thorn, "dissipation.c" calls the fortran subroutine "apply_dissipation.F77" directly without scheduling in CACTUS. I guess the variables between C and fortran become inconsistency in this stage. What do you think? I don't have much knowledge to call fortran subroutine from directly c language. So I need comments from expert. Kentaro TAKAMI

6 23

meeting minutes
by Roland Haas 04 Mar '13

04 Mar '13

Present were: Frank, Yosef, Peter, Ian, Eloisa, Roland failing tests: * Erik and Eloisa are looking into thorn PeriodicCarpet APS meeting: * try to all meet for dinner on one day Yours, Roland _______________________________________________ Users mailing list Users(a)einsteintoolkit.org http://lists.einsteintoolkit.org/mailman/listinfo/users

1 0

New thorn PeriodicCarpet
by Erik Schnetter 03 Mar '13

03 Mar '13

We just added a new thorn PeriodicCarpet to the Einstein Toolkit. Unsurprisingly, this thorn provides periodic boundary conditions for simulations that use Carpet. PeriodicCarpet is implemented using Carpet's communication infrastructure, and is thus significantly more flexible and efficient than the existing thorn Periodic. In particular, simulations with irregular grid structures or with refined regions near or crossing the periodic boundaries will benefit from PeriodicCarpet. -erik -- Erik Schnetter <schnetter(a)cct.lsu.edu> http://www.perimeterinstitute.ca/personal/eschnetter/

1 0

Einstein Toolkit Meeting Reminder
by Frank Loeffler 02 Mar '13

02 Mar '13

Hi Please consider joining the weekly Einstein Toolkit phone call at 10 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/ In short: the number is (+1) 225-578-4942 or (+1) 866-573-0359 and the conference id is 118682#. Current status: - Trunk has three failing testsuites. - Two because of an issue with the parameter file parser (not parsing 'inf' in 'trunc(atan(-inf))' (do we need that anyway?) - One in the thorn (PeriodicCarpet), which was just added Please make any efforts to fix these problems - Tickets that have been closed last week: - IOUtil::out_dir now defaults to "$parfile" - There are versions of CCTK_WARN that never return (and let the compiler know about that fact) - PeriodicCarpet was added to the ET - XARGS can be used as configuration variable to specify the location of a suitable xargs installation (only found to be necessary on one specific machine: pandora at LSU) - hdf5 index files for checkpoints will now be deleted along with their checkpoints (if this option is used) - There was an issue with simulations not restarting correctly by simfactory if the latter was updated in the meantime. This has been fixed. - 9 Tickets are pending review at the moment. Please take a few minutes of your time to see if you could help reviewing one of these proposed fixes/improvements. [1] - I suppose a lot of people on this list will go to the APS meeting in April. The talk notifications had been sent a while ago and the early bird registration deadline is in the past. While I am sure we all will be quite busy those days it would nevertheless be nice to get most of us together one evening for dinner. This does not have to be (and hopefully isn't, at least not too much) about work. Leave your laptop, but bring some stories to share. Would there be interest in such an evening? As always, please feel free to ask any question somehow related to the toolkit. Frank Loeffler [1] https://trac.einsteintoolkit.org/query?status=review&col=id&col=summary&col…

1 0

Developer workshop summer 2013
by Frank Loeffler 02 Mar '13

02 Mar '13

Hi, As most of the developers probably know, there will be a developer meeting after the new-users "day", starting Saturday, Jul 27th. There seems to be consensus that this should at least last until Sunday, but it was not clear yet if the following Monday (Jul 29th) should be included as well. Please express your opinion in the following poll. http://doodle.com/ngyb3pyhfcg36b3v Frank Loeffler

1 0

2026

2025

2024

2023

2022

2021

2020

2019

2018

2017

2016

2015

2014

2013

2012

2011

2010

Users March 2013