[Users] problems with AHFinderDirect

[Eloisa Bentivegna]

On Jun 14, 2012, at 12:01 PM, Vassilios Mewes wrote:

> Hello all,
> 
> when using the AHFinderDirect thorn in a simulation of a relativistic wind past a TOV neutron star, i get the following error message:
> 
> INFO (AHFinderDirect): proc 0: searching for horizon 1/1
> WARNING level 0 in thorn AHFinderDirect processor 0 host permeability.daa.uv.es
>   (line 78 of /Users/vass/programs/Cactus/arrangements/EinsteinAnalysis/AHFinderDirect/src/jtutil/error_exit.cc): 
>   -> ***** row_sparse_Jacobian__UMFPACK::solve_linear_system():
>         error return status=1 from umfpack_numeric() routine
> 
> is that an indication that umfpack is not installed correctly (i was never prompted to install it manually and the compilation of the Einstein toolkit [Maxwell release] went on smoothly without any errors), or rather that something is wrong trying to find the horizon? (there should be an horizon, because the lapse goes to 0 fairly quickly, after which the simulation eventually crashes)

Hi Vassili,

this error usually comes up when the arguments to umfpack_numeric() are not numbers (as would happen, for instance, if the metric had become singular). Could you check that your 3+1 variables are finite? Thorn NaNChecker could help you do that.

Eloisa