[Users] ML and ADMConstraints

Luca Baiotti baiotti at ile.osaka-u.ac.jp
Fri Mar 23 01:54:39 CDT 2012


Hello Roland,

thanks for the explanation.

On 23/3/12 10:44 AM, Roland Haas wrote:
> Hello Luca, all,
>
>>    From this I understand that ADMConstraints should not be used with ML.
>> In order to prevent accidental use, would it be possible to insert a
>> parameter check in ML that warns against ADMConstraints? Or at least a
>> note in the README file and documentation of ADMConstraints?
> The default parameters of TmunuBase should work with  ADMConstraints.
> The TmunuBase parameter Erik is referring to is
> TmunuBase::support_old_CalcTmunu_mechanism which is on by default (for
> backwards compatability, this might change in the future!). If
> support_old_CalcTmunu_mechanism==yes then ADMConstraints should pick up
> Tmunu from CalcTmunu.inc (as Ttt, Ttx etc, see
> ADMConstraints/src/ADMConstraints.F). Do you know if
> TmunuBase::support_old_CalcTmunu_mechanism is set in your parameter file?

I set that parameter to no. I tried to set it to yes and the values are 
correct indeed.

> Also note that the "old" mechanism is terribly slow since Cactus checks
> for each grid point whether TmunuBase is active before executing the its
> part of the include file (only for "USES INCLUDE" code include files,
> not for "USES INCLUDE HEADER" header include files). Since the checking
> involves walking a linked list and stricmp() calls, you can spend a good
> fraction of you computation time in it :-) .
>
> A good way to prevent accidental use with wrong parameter settings might
> be add a warning (level 1 or 0) to the "else" branch of the "if
> (stress_energy_2_state .ne. 0) then" section in
> TmunuBase/TmunuBase_CalcTmunu.inc which would trigger when the mechanism
> is used (independent of which thorn tries to use it).

All right.

Luca


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