# [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/
>>
>>
>>
>>
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>>
>>
>>
>> --
>>
>>
>>
>> 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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