[Users] Phone Call Mon, Nov 8th

[Peter Diener]

Hi,

A bit more information to add to the confusion. Using the git version of 
Carpet, I was not able to get the same results on 1 and 2 processors. Not 
even going to a full grid as Erik did. However, with the added 
interpolation debug output built into AHFinderDirect I do notice a 
somwehat different behavior. With PUGH I see differences (within 11-12 
decimal places) in the interpolation results before the first call to the 
linear solver. With Carpet I don't. There the first differences appear 
in the horizon coordinates after the first linear solve. So with Carpet it 
appears that the linear solver gets the same data on 1 and 2 procs but 
finds a different solution.

I get the same results using PUGH and Carpet on 1 processor. The results 
on 2 processors using PUGH and Carpet differs from the 1 processor results 
and with each other.

Also the results differ depending on whether bitant or full mode is used
even on 1 processor.

Cheers,

   Peter

On Mon, 8 Nov 2010, Erik Schnetter wrote:

> On Mon, Nov 8, 2010 at 12:07 PM, Eloisa Bentivegna <bentivegna at cct.lsu.edu>
> wrote:
>       On Nov 8, 2010, at 5:58 PM, Erik Schnetter wrote:
>
>       > I tested further, using Carpet instead of PUGH. I believe that
>       the problem is in the single processor case of PUGHInterp, i.e.
>       that the 2 process results are actually correct. Carpet gives
>       identical answers for 1 and 2 processes.
> 
> Interesting, we concurrently did the same test, but I still did get
> differences. Can you send me your parameter file?
> 
> 
> I used the Mercurial version of Carpet, and I disabled bitant mode. I attach
> my parameter file.
> 
> -erik
> 
> --
> Erik Schnetter <schnetter at cct.lsu.edu>   http://www.cct.lsu.edu/~eschnett/
> 
> 
>