[Users] Multiple time levels

[Steven R. Brandt]

OK, so copying data in CCTK_PRESTEP seems to work.

My next question is, I think, trickier... My par file looks something 
like this

Carpet::time_refinement_factors = "[1,1]"
Time::timestep_method = "given"
Time::timestep = 0.05
Carpet::prolongation_order_time = 0
...

Unfortunately, when I try to run the code I get this:

WARNING level 0 from host 18-5e-f-12-9b-2a.wlan.lsu.edu process 0
   while executing schedule bin (none), routine (no thorn)::(no routine)
   in thorn CarpetLib, file 
/home/sbrandt/cactus/CactusFW/arrangements/Carpet/CarpetLib/src/gdata.cc:375:
   -> Internal error: extrapolation in time. variable=FUNWAVE::eta  
time=0  times=[0.050000000000000003]
cactus_sim: 
/home/sbrandt/cactus/CactusFW/arrangements/Carpet/Carpet/src/helpers.cc:269: 
int Carpet::Abort(const cGH*, int): Assertion `0' failed.

It's trying to get data from the same time level, but it seems to only 
have the wrong one.

My theory is that prolongation_order_time = 1 is going to give me what I 
want, because it's going to prolong to one of the endpoints (the code 
runs, at least). Does this mean that prolongation_order_time = 0 is broken?

Cheers,
Steve

On 01/05/2016 01:06 PM, Erik Schnetter wrote:
> Steve
>
> If a grid variable has multiple time levels, then it will be cycled at
> the beginning of every time step. You need to copy the past to the
> current time level after time level cycling to preserve the previous
> behaviour.
>
> -erik
>
>
> On Tue, Jan 5, 2016 at 1:46 PM, Steven R. Brandt <sbrandt at cct.lsu.edu> wrote:
>> In the code I'm working on, I have a set of variables living at a single
>> timestep. For various reasons, I want to shift to having them at two
>> timelevels, but simply making the change in interface and schedule
>> results in failure to run old test suites. Is there a recipe I should be
>> following to make this work?
>>
>> Cheers,
>> Steve
>> _______________________________________________
>> Users mailing list
>> Users at einsteintoolkit.org
>> http://lists.einsteintoolkit.org/mailman/listinfo/users
>
>