[CIG-SHORT] Intermediate Results

[Brad Aagaard]

Bobby,

The primary ways to reduce runtime for quasistatic simulations are:

(1) choose appropriate tolerances for the KSP (and SNES) solves (using 
unnecessarily small values leads to more iterations than necessary)

(2) use the field split solver with the custom fault preconditioner (see 
examples/3d/tet4/step03)

(3) run in parallel

For dynamic simulations with explicit time stepping, only (3) applies.

Regards,
Brad


On 03/06/2013 02:36 PM, BOK10 at pitt.edu wrote:
> Hi Charles,
>
> It takes pretty long for a simulation to finish processing, and I was
> hoping to split the simulation up into parts so I can come back to it
> later. It's not a necessity, but more a convenience issue.
>
> I think I'll just continue on with running it overnight.
>
> Thanks,
> Bobby
>
>
>
>> Hi Bobby,
>>
>> I'm not quite sure what you have in mind.  If you're running any sort of
>> viscoelastic problem, you would need to save the entire state at the end
>> of each run.  I don't see what benefit there would be from doing this,
>> since you would still need to finish each run to get all the state
>> variables at the end of each chunk, and then feed them into the next
>> simulation as initial state variables.
>>
>> If your problem is completely elastic, I suppose you could run them in the
>> way you're suggesting, and then use linear superposition to obtain the
>> final result.  What is your reason for wanting to break up the simulation?
>>
>> Cheers,
>> Charles
>>
>>
>> On 7/03/2013, at 11:22 AM, BOK10 at pitt.edu wrote:
>>
>>> Is it possible to split a simulation into parts? I'm running my model
>>> for
>>> 400 years at 5 year time intervals, but is it possible to split it to
>>> 100
>>> year chunks and run them serially?
>>>
>>> Bobby
>>>
>>>
>>>
>>>
>>> _______________________________________________
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>>
>> Charles A. Williams
>> Scientist
>> GNS Science
>> 1 Fairway Drive, Avalon
>> PO Box 30368
>> Lower Hutt  5040
>> New Zealand
>> ph (office): 0064-4570-4566
>> fax (office): 0064-4570-4600
>> C.Williams at gns.cri.nz
>>
>>
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