Users May 2011

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25 discussions

CarpetMask problem (was: Re: [Commits] [svn:einsteintoolkit] Paper_EinsteinToolkit_2010/examples/bbh/ (Rev. 85))
by Erik Schnetter 12 May '11

12 May '11

Bruno The problem was indeed that CarpetReduce overwrote the mask. While setting up the mask, CarpetReduce uses a temporary integer grid function to store which octant of which cell is active. This is later converted into the real grid function that people use. CarpetMask needed to set up this integer grid function instead of the real grid function. Please update Carpet and try again. -erik On Wed, May 11, 2011 at 6:39 PM, Bruno Coutinho Mundim <bcmsma(a)astro.rit.edu> wrote: > Hi Erik, > > I have attached the schedule output for this run. I suspect CarpetReduce > is somehow overwriting the weight function set by CarpetMask. > > Thanks, > Bruno. > > Erik Schnetter wrote: >> >> That is strange. I assume some other routine overwrites it. Can you >> check the schedule? Is there another CarpetMask or CarpetReduce >> routine acting on the mask afterwards? >> >> -erik >> >> On Wed, May 11, 2011 at 1:30 PM, Bruno C. Mundim <bcmsma(a)astro.rit.edu> >> wrote: >>> >>> Thanks, Erik! On a related note: I checked if CarpetMask was setting >>> weight[ind]=0 inside the horizons and it seems to do so correctly. >>> However CarpetReduce::weight still do not reflect that. Its output >>> still doesn't have the horizons masked out. >>> >>> Thanks, >>> Bruno. >>> >>> Erik Schnetter wrote: >>>> >>>> On Wed, May 11, 2011 at 12:53 PM, Bruno C. Mundim <bcmsma(a)astro.rit.edu> >>>> wrote: >>>>> >>>>> Hi Roland: >>>>> >>>>> Roland Haas wrote: >>>>>> >>>>>> Hello Bruno, >>>>>> >>>>>>> a) Its evolution is stopped with Nans around 8.6M. Nans appear to >>>>>>> come >>>>>>> from the BSSN fields, but still needs further investigation. >>>>>> >>>>>> Hmm I could evolve the qc0 example in McLachlan. Maybe there are >>>>>> differences in the parameter file that make the error "obvious". >>>>>> >>>>> A few obvious changes that I can think of: >>>>> >>>>> 1) I reduced the number of spherical surfaces from 5 to 3. Now the >>>>> puncture tracker uses surfaces 0 and 1, AHFinderDirect track those >>>>> surfaces and load AH related info there. QLM, CarpetTracker and >>>>> CarpetMask uses those 2 surfaces then. I will go back to 5 surfaces >>>>> as it was set before. Maybe I am missing some subtle scheduling order >>>>> here. I don't know. >>>>> >>>>> 2) I added a few general parameters I am used to use to CarpetInterp, >>>>> CarpetLib and CarpetRegrid2. >>>>> >>>>> 3) From a discussion I had with Peter on the ET workshop, I decided >>>>> to change the AHFinderDirect interpolator to Hermite. >>>>> >>>>> So I will switch back to what it was and avoid to do so many changes >>>>> at once! :) However I find strange that these changes could be the >>>>> cause of what I am seeing. >>>>> >>>>> >>>>>>> c) When CarpetReduce::weight is output, its values seem strange to >>>>>>> me. >>>>>>> Most of the domain has 1/2 set. A few points close to the boundary >>>>>>> 1/4 >>>>>>> and the boundaries 0 (physical and ghost). No mask out values inside >>>>>>> AH is shown, ie they still are set to 1/2. These values seem to make >>>>>>> more sense to AMR restriction operations. >>>>>> >>>>>> Are you maybe looking at the z=0 plane? That plane has a weight of 1/2 >>>>>> since only half of the volume of each cell is used when eg. computing >>>>>> the simulation volume. I have never used CarpetMask myself (but have >>>>>> written a similar thorn of my own... would have paid to look into >>>>>> Carpet >>>>>> first I guess :-) ) >>>>>> >>>>> Yes I was looking at the z=0 plane and had refection symmetry set up! >>>>> Thanks for pointing this out. If we go out of the plane then the >>>>> weight=1.0 values show up. A more careful look into the data, I noticed >>>>> the zeros are set in the buffer zones indeed with the exception of the >>>>> third point (ghostzone=3) in the domain (from the AMR boundary) that >>>>> has >>>>> its value set to 1/4. Do you know why? >>>> >>>> For some reason that I currently cannot recall, the ghost zones in the >>>> mask may be set to 1 instead of 0. However, ghost zones are ignored >>>> anyway by a different mechanism when reducing (by using cctk_bbox and >>>> cctk_nghostzones). >>>> >>>> The particular values indicate how much of the "control cell" >>>> surrounding this grid point should be taken into account when >>>> reducing. If the value is 1/4, then you may be looking at an edge >>>> point (e.g. and x-y edge in the z=0 plane), where 3/4 of the control >>>> cell are already covered by the corresponding coarse grid. >>>> >>>> One important test is that the sum of all weights times the grid cell >>>> volume equals the total volume of the simulation domain. If you look >>>> into the simulation log output and search for "volume" there, you >>>> should find a corresponding statement. >>>> >>>> -erik -- Erik Schnetter <schnetter(a)cct.lsu.edu> http://www.cct.lsu.edu/~eschnett/

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Re: [Users] [Commits] [svn:einsteintoolkit] Paper_EinsteinToolkit_2010/examples/bbh/ (Rev. 85)
by Roland Haas 11 May '11

11 May '11

Hello Bruno, > a) Its evolution is stopped with Nans around 8.6M. Nans appear to come > from the BSSN fields, but still needs further investigation. Hmm I could evolve the qc0 example in McLachlan. Maybe there are differences in the parameter file that make the error "obvious". > c) When CarpetReduce::weight is output, its values seem strange to me. > Most of the domain has 1/2 set. A few points close to the boundary 1/4 > and the boundaries 0 (physical and ghost). No mask out values inside > AH is shown, ie they still are set to 1/2. These values seem to make > more sense to AMR restriction operations. Are you maybe looking at the z=0 plane? That plane has a weight of 1/2 since only half of the volume of each cell is used when eg. computing the simulation volume. I have never used CarpetMask myself (but have written a similar thorn of my own... would have paid to look into Carpet first I guess :-) ) Yours Roland

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Meeting minutes (fwd)
by Roland Haas 09 May '11

09 May '11

Meeting minutes: Present were: Frank, Peter, Erik, Ian, Eloisa, Josh, Yosef, Bruno, Tanja ET paper: * single spinning BH example: runs finished, Peter will add results this week * BBH runs have a parameter file that is ready to submit, Bruno will do so today * TOV star was done, can see fundamental mode very easily, higher harmonics are not easily visible. Need other full GR code result to compare to (maybe Christian Evan O'Connor's and Ott's GR1D code). * comsology: figures were missing, have been added since the call * agree to publish in CQG since the intended audience is numerical relativists fall workshop: * target audience is graduate students * will try to get funding for student travel from funding agencies (Josh) * topics will include: introduction to BSSN, general relativistic hydro, MHD, Cactus, Alpaca, VisIt * possible speakers listed in wiki on ET website * time: Oct 14th-18th (fall break for LSU GT) * location: GT or LSU, need room for 25 persons, GT will check if lecture hall can be used. LSU has room available. * accomodation: prefer inexpensive location (since the workshop is rather long). Atlanta should have places in the $40/night range which however require a commute of about 30-45min. Yours, Roland

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Re: [Users] Einstein Toolkit Meeting Reminder
by Frank Loeffler 08 May '11

08 May '11

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/info/support/ I short: the number is (+1) 225-578-4942 or (+1) 866-573-0359 and the conference id is 118682#. Some points of tomorrows discussion will be: 1) ET paper plan: - Most text included, or sections get reassigned - All text included, data from example sections mostly there - Results from example sections included, or dropped - Text and data complete - "public review" - Addressed incoming comments, publish along with new release I have dropped the dates on this plan for this email. We have somewhat completed point one, and need to get point two done. 2) Where to publish? 3) Planning for fall-workshop: - What exactly do we want to do? -> Once we figured that out we might be able to ask for financial support. -> Who should come? -> What should be done/taught? -> Where should that happen? (LSU?) -> When should that happen? Frank Loeffler

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Carpet Mercurial
by Frank Loeffler 01 May '11

01 May '11

Hi, With the new release out of the way, the mercurial(hg)-version of Carpet will replace the git-version in the development version of the Einstein Toolkit. Write access will be provided as was in the past: using ssh keys. Ask Erik to get access. Anonymous read access is available via the following URL, both to be used for cloning, and for browsing the repository if you so like. http://www.carpetcode.org/hg/carpet/ We will change the thornlist of the development version of the Einstein toolkit to use the hg version - please be aware of this when you update your configuration. Frank Loeffler

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Users May 2011