[Users] Meeting Minutes for 2015-06-22

[Ian Hinder]

On 24 Jun 2015, at 12:24, Eloisa Bentivegna <bentivegna at cct.lsu.edu> wrote:

> On 23/06/15 22:59, Roland Haas wrote:
>> Hello all,
>> 
>> Present were: Peter, Steve, Christine, Ian, Elo, Matt, Roland
>> 
>> Tickets:
>> 1667 include elliptic solver:
>> * several options present themselves (1) use CactusEllitpic (2) use new
>> arrangement Elliptic (3) use a arrangement collecting the author's
>> thorns (4) postpone the decision
>> * Roland objects to adding the solver to CactusElliptic since it is
>> explicitly tied to Carpet and Carpet is not part of Cactus
>> * a general issue exists in that we either have CactusXXX arrangements
>> or EinsteinXXX arrangements but no neutral XXX arrangement
> 
> Thanks Roland for summing up nicely the result of the discussion. It  
> is true that historical reasons are creating a bit of an impasse with  
> arrangements named *Elliptic: the existing CactusElliptic implies more  
> about its thorns than the fact that they apply to elliptic problems;  
> on the other hand, the creation of additional *Elliptic arrangements  
> would make life harder for (and potentially hide tools from) users who  
> are just looking for an elliptic solver.

Putting it in an institution-specific arrangement would do the same.  In fact, it could be worse, as the name of the arrangement would not reflect the content, but the origin of the code, making it harder to find "an elliptic solver", if you didn't know where it was originally developed.

> I am now leaning towards a mix of (3) and (4), perhaps under the form  
> of a *Thorns or *Development arrangement (replace * with "Cosmo", or  
> my current institution, or any other meaningful prefix). It seems to  
> me that arrangements named this way have been used as incubators for  
> newborn thorns, which may or may not be moved elsewhere once it's  
> clear where (or whether at all) they belong inside Cactus or the ET.
> 
> For instance, would anyone object to a CataniaThorns arrangement?

I wouldn't object, but it wouldn't be my first choice.  The reason is that software authors tend to move between institutions, and code is often developed collaboratively between authors from different institutions.  Very little of the code in AEIThorns is now developed by people at AEI, nor that in LSUThorns by people at LSU, and the TAT arrangements have nobody at TAT at all.  So my preference would still be to have a place where "community" thorns can be placed.  If this shouldn't be in an arrangement with a Cactus prefix, then I think we should create new arrangements.

$ ls AEIThorns LSUThorns TAT
AEIThorns:
ADMMass			PunctureTracker		Trigger
AEILocalInterp		SystemStatistics

LSUThorns:
PeriodicCarpet		QuasiLocalMeasures	SummationByParts	Vectors

TAT:
TATPETSc	TATelliptic

The non-GR-related thorns would all be covered by a "Numerical" and a "Utils" arrangement.  If the Cactus* arrangements are off-limits, and the Einstein* arrangements are not appropriate due to the code not being related to the Einstein equations, then we should have an alternative for this sort of code.  Note: I'm not suggesting that we actually move the above thorns (though for AEIThorns and LSUThorns we want to stop using the respective SVN servers, so we may take the opportunity to do so), I'm just illustrating how the thorns would fit into my proposed arrangements.

If Numerical and Utils are too generic, maybe we could have a prefix, such as Community, User, or something like that. But maybe Numerical and Utils are OK.

-- 
Ian Hinder
http://members.aei.mpg.de/ianhin

-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.einsteintoolkit.org/pipermail/users/attachments/20150624/4cf7d20e/attachment.html