[Users] problem with first example simulation with ETK

Ian Hinder ian.hinder at aei.mpg.de
Mon Jan 23 15:11:35 CST 2012


On 23 Jan 2012, at 14:57, Jose Fiestas Iquira wrote:

> Hello,
> 
> Regarding the Binary Black Hole coalescence example from the ETK.
> 
> In the BH diagnostics files are columns with quadrupole terms, which
> are not constant. Do you know of some tool in ETK to calculate the GW
> emission from these terms?

No, not that I am aware of.  These are the quadrupole moments of the individual apparent horizons, rather than the quadrupole moment of the system as a whole.  The gravitational wave emission can be computed by using the WeylScal4 and Multipole thorns.  These give you the spherical harmonic multipoles of Psi4 (e.g. l = 2, m = 2 is the dominant one), which can then be converted to strain by "two integrations in time" [this is actually quite subtle and hard to get right - see  Reisswig and Pollney, arXiv:1006.1632, for an overview and solution).


> 
> Thanks,
> Jose
> 
> On Tue, Jan 17, 2012 at 5:18 AM, Ian Hinder <ian.hinder at aei.mpg.de> wrote:
>> 
>> On 17 Jan 2012, at 13:37, Jose Fiestas Iquira wrote:
>> 
>> The Einstein Analysis guide is very useful. I found here
>> http://einsteintoolkit.org/documentation/ThornGuide/ThornGuidech142.html#x159-2520000P8.4
>> the units used in 'Hydrobase'.
>> 
>> If I assume these are the units for all thorns, I obtain from data in
>> BH_diagnostics.ah1.gp a unit of distance of about 1 Km. To estimate
>> the time I am using a mass of ~0.5 M_sun for both BHs (m_irreducible
>> ?) , and I read a final time (cctk_time) ~ 1microsec. Are these
>> quantities in the usual range?
>> 
>> 
>> The length unit is G M / c^2 and the time unit is G M / c^3.  For M = M_sun,
>> I get the length unit as 1.5 km and the time unit as 4.9 us.  The final time
>> in the simulation is 100 M (i.e. 100 G M / c^3), which would be 0.5 ms.
>> 
>> 
>> 
>> 
>> 
>> 
>> Jose
>> 
>> 
>> On Tue, Jan 17, 2012 at 4:04 AM, Jose Fiestas Iquira <jafiestas at lbl.gov>
>> wrote:
>> 
>> I sent the wrong file, here is the right one.
>> 
>> 
>> $ hg tip
>> 
>>  gives me:
>> 
>> -----------------------------------------------------
>> 
>> changeset:   3421:dff4df2b3687
>> 
>> tag:         tip
>> 
>> user:        Erik Schnetter <schnetter at cct.lsu.edu>
>> 
>> date:        Thu Jan 12 14:11:27 2012 -0500
>> 
>> summary:     CarpetLib: Allocate space for dstbox before
>> 
>> restricting/prolongating
>> 
>> 
>> [40514 refs]
>> 
>> -----------------------------------------------------
>> 
>> 
>> I copied this version from:
>> 
>> 
>> ./GetComponents -a
>> 
>> http://svn.einsteintoolkit.org/manifest/trunk/einsteintoolkit.th
>> 
>> 
>> Thanks,
>> 
>> Jose
>> 
>> 
>> 
>> 
>> 
>> On Tue, Jan 17, 2012 at 1:13 AM, Ian Hinder <ian.hinder at aei.mpg.de> wrote:
>> 
>> 
>> On 16 Jan 2012, at 23:21, Jose Fiestas Iquira wrote:
>> 
>> 
>> Thanks, I am attaching the output file.
>> 
>> 
>> 
>> The output file looks fine - I can't see any problem with the simulation.
>> 
>>  According to the output file, it reached t = 100 M, and in the parameter
>> 
>> file that is listed as cctk_final_time, so all looks well!
>> 
>> 
>> I did copy the development version. As I can see, it was already
>> 
>> fixed, so I should not get this warning, since I copied the
>> 
>> development version.
>> 
>> 
>> 
>> Yes, if you are using the current development version, then I don't know why
>> 
>> you get the warning.  Can you check which version of Carpet you have by
>> 
>> doing
>> 
>> 
>> cd repos/carpet
>> 
>> hg tip
>> 
>> 
>> to be sure you are using the development version?
>> 
>> 
>> Is  the puncture tracker not a better way to plot BH trajectories.
>> 
>> 
>> 
>> It's cheaper to use the puncture tracker, because computing the horizon
>> 
>> centroid is more expensive, but it has to be done every iteration, whereas
>> 
>> the horizon can be found less frequently.  For comparison with
>> 
>> point-particle results, I don't think it makes much difference; the results
>> 
>> are gauge dependent anyway so differences on the order of the horizon size
>> 
>> cannot be interpreted physically.  Since the parameter file already has
>> 
>> horizon-finding built in, it is easier for you to use that.
>> 
>> 
>> If you want to figure out how to add the puncture tracker to the simulation,
>> 
>> you can start with these parameters:
>> 
>> 
>> ActiveThorns = "PunctureTracker"
>> 
>> 
>> PunctureTracker::track                      [0] = yes
>> 
>> PunctureTracker::initial_x                  [0] = $xp
>> 
>> PunctureTracker::which_surface_to_store_info[0] = 0
>> 
>> PunctureTracker::track                      [1] = yes
>> 
>> PunctureTracker::initial_x                  [1] = $xm
>> 
>> PunctureTracker::which_surface_to_store_info[1] = 1
>> 
>> 
>> IOASCII::out0D_vars = "PunctureTracker::pt_loc"
>> 
>> 
>> Replace $xp and $xm with the initial x coordinates of the +x and -x
>> 
>> punctures (this will be \pm TwoPunctures::par_b).  You then need to choose
>> 
>> two spherical surfaces
>> 
>> (https://docs.einsteintoolkit.org/et-docs/Einstein_Toolkit_standards) which
>> 
>> are not being used currently to store the puncture locations in.  If there
>> 
>> is already 0D output, just add the puncturetracker variable separated with a
>> 
>> space.
>> 
>> 
>> I
>> 
>> did some plots, what are really the combinations xx, xy, xz, yy, zz ?
>> 
>> Are they related to the trajectories of one BH (projections)? What
>> 
>> about the second BH?
>> 
>> 
>> 
>> You should have BH_diagnostics.ah1.gp and BH_diagnostics.ah2.gp.  These
>> 
>> correspond to the first and second BHs.  If you look at the top of these
>> 
>> files, you will see an explanation of the columns.  More information about
>> 
>> each column is available in the AHFinderDirect documentation
>> 
>> (http://einsteintoolkit.org/documentation/ThornGuide/ThornGuidech128.html#x144-2264000O4).
>> 
>>  Specifically, information about the BH_diagnostics output files is
>> 
>> at http://einsteintoolkit.org/documentation/ThornGuide/ThornGuidech128.html#x144-2274000O4.5.5
>> 
>> 
>> To plot the trajectory of one of the BHs, you want to plot column 3 and
>> 
>> column 4 in a parametric plot.
>> 
>> 
>> 
>> Cheers,
>> 
>> Jose
>> 
>> 
>> On Mon, Jan 16, 2012 at 4:39 AM, Ian Hinder <ian.hinder at aei.mpg.de> wrote:
>> 
>> 
>> 
>> On 14 Jan 2012, at 00:41, Jose Fiestas Iquira wrote:
>> 
>> 
>> 
>> Hi Ian,
>> 
>> 
>> I did the changes but it started and finished early. I am attaching
>> 
>> 
>> the qc0-mclachlan.err file. At the end there is a warning in one of
>> 
>> 
>> the Carpet files (mask_test.c)
>> 
>> 
>> 
>> 
>> The warning you see,
>> 
>> 
>> 
>> WARNING level 1 in thorn CarpetReduce processor 0 host qb517
>> 
>> 
>>   (line 120 of
>> 
>> 
>> /home/ettest24/Cactus/arrangements/Carpet/CarpetReduce/src/mask_test.c):
>> 
>> 
>>   -> Simulation domain volume and reduction weight sum differ
>> 
>> 
>> 
>> is a known issue (https://trac.einsteintoolkit.org/ticket/434) which was
>> 
>> 
>> fixed after the last release and the fix is only available in the
>> 
>> 
>> development version.  I believe that the warning is not fatal, and it should
>> 
>> 
>> not have terminated the simulation.  Can you also post the qc0-mclachlan.out
>> 
>> 
>> file?
>> 
>> 
>> 
>> Where can I find the puncture tracker?
>> 
>> 
>> 
>> 
>> The PunctureTracker thorn is part of the Einstein Toolkit thornlist, so you
>> 
>> 
>> should have it already.  However, I think the best thing for you to do
>> 
>> 
>> initially would be to look at the BH_diagnostics files for the apparent
>> 
>> 
>> horizon centroid locations for tracking the locations of the BHs.
>> 
>> 
>> 
>> 
>> 
>> 
>> Thanks,
>> 
>> 
>> Jose
>> 
>> 
>> 
>> On Fri, Jan 13, 2012 at 4:38 AM, Ian Hinder <ian.hinder at aei.mpg.de> wrote:
>> 
>> 
>> 
>> 
>> On 13 Jan 2012, at 12:32, Jose Fiestas Iquira wrote:
>> 
>> 
>> 
>> 
>> Yes, trajectories and wave forms would be enough for now. Which are
>> 
>> 
>> 
>> the names of this files? Many of the .asc files have data like kxx,
>> 
>> 
>> 
>> kxy, kxz, etc. Is there any description of them?
>> 
>> 
>> 
>> 
>> Not that I am aware of.  Files with extension .x.asc are 1D ascii output of
>> 
>> 
>> grid functions from CarpetIOASCII.  kxy is the variable name for the x,y
>> 
>> 
>> component of the extrinsic curvature tensor K.  The waveform file should be
>> 
>> 
>> in mp_psi4_l2_m2_r*.asc where * corresponds to the radius of the extraction
>> 
>> 
>> sphere.  However, looking at the qc0-mclachlan.par file, I see that there is
>> 
>> 
>> no wave extraction switched on.  You should be able to enable wave
>> 
>> 
>> extraction by adding something like the following to the parameter file:
>> 
>> 
>> 
>> 
>> ActiveThorns = "WeylScal4 CarpetInterp AEILocalInterp Multipole"
>> 
>> 
>> 
>> 
>> Multipole::nradii    = 3
>> 
>> 
>> 
>> Multipole::radius[0] = 30
>> 
>> 
>> 
>> Multipole::radius[1] = 40
>> 
>> 
>> 
>> Multipole::radius[2] = 50
>> 
>> 
>> 
>> Multipole::variables = "WeylScal4::Psi4r{sw=-2 cmplx=’WeylScal4::Psi4i’}"
>> 
>> 
>> 
>> Multipole::l_max     = 4
>> 
>> 
>> 
>> WeylScal4::fdOrder   = 4
>> 
>> 
>> 
>> 
>> (I haven't tested this, so let me know if it doesn't work)
>> 
>> 
>> 
>> 
>> I've just found that the usual PunctureTracker thorn is not enabled in this
>> 
>> 
>> example parameter file.  So to look at trajectories you will have to use the
>> 
>> 
>> apparent horizon centroids.  These are in the files BH_diagnostics.ah*.gp.
>> 
>> 
>>  The meanings of the columns are at the top of the files.  You want the
>> 
>> 
>> centroid x and y columns to plot in GnuPlot.
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>> Thanks,
>> 
>> 
>> 
>> Jose
>> 
>> 
>> 
>> 
>> On Fri, Jan 13, 2012 at 12:41 AM, Ian Hinder <ian.hinder at aei.mpg.de> wrote:
>> 
>> 
>> 
>> 
>> On 12 Jan 2012, at 23:46, Jose Fiestas Iquira wrote:
>> 
>> 
>> 
>> 
>> Dear all,
>> 
>> 
>> 
>> 
>> I run the tutorial and found other interesting examples like the
>> 
>> 
>> 
>> McLachlan tool for Binary Black Holes.
>> 
>> 
>> 
>> 
>> Regarding the McLachlan tool,
>> 
>> 
>> 
>> Could somebody help me finding a description of the output? Is all
>> 
>> 
>> 
>> contained in the .asc files? I would like to visualize it.
>> 
>> 
>> 
>> 
>> 
>> Hi Jose,
>> 
>> 
>> 
>> 
>> What sort of output do you want to visualise?  Cactus thorns typically
>> 
>> 
>> 
>> output "lightweight" information such as BH trajectories and waveforms as
>> 
>> 
>> 
>> ASCII, and more heavyweight data -- like gridfunctions -- as HDF5.  For the
>> 
>> 
>> 
>> trajectories (from thorn Puncture Tracker) and waveforms (from Multipole)
>> 
>> 
>> 
>> you can use gnuplot or anything that can read standard ASCII output to
>> 
>> 
>> 
>> visualise them.  For gridfunctions in HDF5 format, I think the easiest way
>> 
>> 
>> 
>> to get started is to use VisIt, for which there is a Carpet plugin (though
>> 
>> 
>> 
>> installing VisIt is sometimes not so easy!).
>> 
>> 
>> 
>> 
>> Does anyone know if the Carpet plugin is distributed with VisIt yet?  I
>> 
>> 
>> 
>> believe that was the intention.
>> 
>> 
>> 
>> 
>> 
>> 
>> Cheers,
>> 
>> 
>> 
>> Jose
>> 
>> 
>> 
>> 
>> 
>> On Wed, Jan 11, 2012 at 7:06 PM, Jose Fiestas Iquira <jafiestas at lbl.gov>
>> 
>> 
>> 
>> wrote:
>> 
>> 
>> 
>> 
>> Thanks to Erik for advise. ETK example simulation run successfully.
>> 
>> 
>> 
>> 
>> 
>> 
>> On Wed, Jan 11, 2012 at 11:49 AM, Jose Fiestas Iquira <jafiestas at lbl.gov>
>> 
>> 
>> 
>> wrote:
>> 
>> 
>> 
>> 
>> Right, it looks good now:
>> 
>> 
>> 
>> 
>> 
>> ./simfactory/bin/sim list-simulations
>> 
>> 
>> 
>> 
>>   static_tov              [ACTIVE (RUNNING), restart 0000, job id 595490]
>> 
>> 
>> 
>> 
>> 
>> Let see how it looks when it finishes. The example was set to 8 hours.
>> 
>> 
>> 
>> 
>> 
>> Thanks,
>> 
>> 
>> 
>> 
>> Jose
>> 
>> 
>> 
>> 
>> 
>> 
>> On Wed, Jan 11, 2012 at 11:45 AM, Erik Schnetter <schnetter at cct.lsu.edu>
>> 
>> 
>> 
>> wrote:
>> 
>> 
>> 
>> 
>> On Wed, Jan 11, 2012 at 2:42 PM, Jose Fiestas Iquira <jafiestas at lbl.gov>
>> 
>> 
>> 
>> wrote:
>> 
>> 
>> 
>> 
>> 
>> The only thing is that now
>> 
>> 
>> 
>> 
>> $ ./simfactory/bin/sim list-simulations
>> 
>> 
>> 
>> 
>> returns
>> 
>> 
>> 
>> 
>> 
>> Error: unknown command list-simulation
>> 
>> 
>> 
>> 
>> Aborting Simfactory.
>> 
>> 
>> 
>> 
>> 
>> Did you really type "list-simulations", and the error message says
>> 
>> 
>> 
>> 
>> "list-simulation" (without the final "s")?
>> 
>> 
>> 
>> 
>> 
>> -erik
>> 
>> 
>> 
>> 
>> 
>> --
>> 
>> 
>> 
>> 
>> Erik Schnetter <schnetter at cct.lsu.edu>   http://www.cct.lsu.edu/~eschnett/
>> 
>> 
>> 
>> 
>> _______________________________________________
>> 
>> 
>> 
>> 
>> Users mailing list
>> 
>> 
>> 
>> Users at einsteintoolkit.org
>> 
>> 
>> 
>> http://lists.einsteintoolkit.org/mailman/listinfo/users
>> 
>> 
>> 
>> 
>> 
>> --
>> 
>> 
>> 
>> Ian Hinder
>> 
>> 
>> 
>> http://numrel.aei.mpg.de/people/hinder
>> 
>> 
>> 
>> 
>> 
>> --
>> 
>> 
>> 
>> Ian Hinder
>> 
>> 
>> 
>> http://numrel.aei.mpg.de/people/hinder
>> 
>> 
>> 
>> 
>> <qc0-mclachlan.err>
>> 
>> 
>> 
>> 
>> --
>> 
>> 
>> Ian Hinder
>> 
>> 
>> http://numrel.aei.mpg.de/people/hinder
>> 
>> 
>> 
>> <qc0-mclachlan.out>
>> 
>> 
>> 
>> --
>> 
>> Ian Hinder
>> 
>> http://numrel.aei.mpg.de/people/hinder
>> 
>> 
>> 
>> --
>> Ian Hinder
>> http://numrel.aei.mpg.de/people/hinder
>> 

-- 
Ian Hinder
http://numrel.aei.mpg.de/people/hinder

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