[Users] McLachlan constraint time levels

[Bruno C. Mundim]

Ok, that seems fair enough, but shouldn't we then tag those groups with 
"prolongation=none"? that would avoid the warning messages when looking 
at 3D output. What do you think?

Thanks,
Bruno.


Erik Schnetter wrote:
> Bruno
> 
> This depends on whether you want the mesh refinement boundaries of the
> constraint variables be interpolated from the next coarser grid, or
> remain undefined/set to zero. In principle, these boundaries are not
> important if you are looking for 3D output, but if you want to look at
> reductions then you will need time interpolation. However, this
> requires in addition that the constraints be calculated at every
> iteration, and is thus expensive both in terms of memory requirements
> and computing time requirements. Most people are therefore fine with
> undefined prolongation boundaries and only look at e.g. 1D output,
> ignoring the ghost and boundary points.
> 
> -erik
> 
> On Wed, Feb 9, 2011 at 5:34 PM, Bruno Coutinho Mundim
> <bcmsma at astro.rit.edu> wrote:
>> Hi,
>>
>> I am receiving the messages of the following kind in my simulation with
>> McLachlan:
>>
>> (line 1084 of ./Cactus/arrangements/Carpet/CarpetReduce/src/reduce.cc):
>>   -> Grid function "ML_BSSN::H" has only 1 time levels on refinement
>> level 0; this is not enough for time interpolation
>>
>> and it is indeed true that the constraint variables has 1 time level only:
>>
>> CTK_REAL ML_Ham type=GF timelevels=1 tags='tensortypealias="Scalar"
>> tensorweight=0'
>> {
>>   H
>> } "ML_Ham"
>>
>>
>> I was wondering if we shouldn't be using 3 time levels instead.
>>
>> Thanks,
>> Bruno.
>> _______________________________________________
>> Users mailing list
>> Users at einsteintoolkit.org
>> http://lists.einsteintoolkit.org/mailman/listinfo/users
>>
> 
> 
>