[dune-pdelab] some problems in dune

[Rebecca de Cuveland]

Hey Robert,
could you please send some more verbose output? (verbosity 3 or 4 for 
AMG and 1 for linear solver). normally this is the last parameter of the 
constructors.
I would like to see the initial defect, end defect and some more 
information about the AMG.
Thanks,
Rebecca

-- 
Rebecca de Cuveland
Universität Heidelberg
Interdisziplinäres Zentrum für Wissenschaftliches Rechnen
Im Neuenheimer Feld 368, 69120 Heidelberg
Tel: 06221/548890   Fax: 06221/548884
e-mail: <rebecca.cuveland at iwr.uni-heidelberg.de>

On 31.10.2014 10:17, Robert Jendrny wrote:
> Hey,
>
> ok, here you get the output for CG_AMG_SSOR (first line: Vertices, 2nd 
> line: elements, 3rd line: convergence rate, 4th line: solveriterations)
> This solver is the fastest in time, but the iteration number 
> "explodes" ;-)
>
> In "theory" i learned that the iteration number should be nearly 
> constant ... but this I learned for GMG and not for AMG ... But they 
> should behave in the same way
>
> Robert
>
>
> On 10/30/2014 08:25 PM, Rebecca de Cuveland wrote:
>> Hey,
>>
>> could you also give us the output of your code? Sometimes the 
>> calculation depend on the installed software on ones computer…
>> Thanks,
>>
>> Rebecca
>> Am 30.10.2014 um 15:18 schrieb Robert Jendrny 
>> <Robert.Jendrny at math.tu-dortmund.de>:
>>
>>> Hi again,
>>>
>>> maybe the fully code would be more helpful ;-)
>>>
>>> All the files which end with "_orig.hh" are the original ones from 
>>> the course which I changed in the files with missing '_orig'
>>>
>>> Cya
>>> Robert
>>>
>>> On 10/30/2014 03:14 PM, Robert Jendrny wrote:
>>>> Hi Rebecca,
>>>>
>>>> thank you for your answer ...
>>>>
>>>> I am working with the code from pdelab exercise2, example02 (Dune 
>>>> course this year - 2014)
>>>> I hope the attached files are enough
>>>>
>>>> The most important file is example02_Q1.hh, there everything is 
>>>> calculated
>>>> I want to solve Poisson (-Laplace(u) = 1) on unit square with AMG
>>>>
>>>> For Q1 I nearly get independent numbers of iterations for mesh size 
>>>> h, h/2, h/4,.... which is fine
>>>>
>>>> But If I change Q1 to Q2, the numbers of iterations "explode" if 
>>>> the mesh gets finer and finer
>>>>
>>>> Maybe someone can fix it ;-)
>>>>
>>>> Bye,
>>>> Robert
>>>>
>>>> On 10/30/2014 03:00 PM, Rebecca de Cuveland wrote:
>>>>> Hey Robert,
>>>>> perhaps you can show us your program and output? (verbosity 3 or 4 
>>>>> for AMG and 1 for linear solver)
>>>>> AMG is quite sensible for the used options. I only use Q1, but as 
>>>>> far as I know Q2 should also work...
>>>>> Bye,
>>>>> Rebecca
>>>>>
>>>>
>>>
>>> -- 
>>> Robert Jendrny
>>> B.Sc. Technomathematik
>>>
>>> TU Dortmund, Fakultät für Mathematik
>>> LS III: Angewandte Mathematik und Numerik
>>> M 1020, Vogelpothsweg 87, 44227 Dortmund
>>> robert.jendrny at math.tu-dortmund.de
>>>
>>> <pdelab-exercise2-sol.zip>
>
>