[Dune] Re: Reference UG
Oliver Sander
sander at mi.fu-berlin.de
Tue Aug 9 09:23:50 CEST 2005
Hi Sreejith!
The Dune numbering is not supposed to match the UG numbering.
Especially the UG numbering of the hexahedra is not easily
generalizable to more space dimensions. Therefore the UGGrid
implementation does some renumbering when being queried about
edge and vertex numbers. Only the numbering for
the prism and the pyramid are supposed to be the same, and
even there I am not sure this is a good idea.
If you want to make sure that all grid implementations comply
with the official numberings you should integrate appropriate
test. IMHO that would be a very good thing.
I hope that helps,
Oliver
************************************************************************
* Oliver Sander ** *
* Freie Universität Berlin ** email: sander at math.fu-berlin.de *
* Institut für Mathematik II ** phone: + 49 (30) 838 75217 *
* Arnimallee 2-6 ** fax : + 49 (30) 838 54977 *
* 14195 Berlin, Germany ** URL : www.math.fu-berlin.de/~sander *
************************************************************************
On Mon, 8 Aug 2005, Sreejith Pulloor Kuttanikkad wrote:
> Hai oliver,
>
> Today I met stefan to know about the reference numbering of all the elements
> in ug grid and he recommended me to look into the element.c in ug/gm
> where all the definition of local variable given. so i tried to
> interpret the local variable information from that file but i found it
> not agreeing with the reference elements in dune page.
>
> for example when we look at
> static GENERAL_ELEMENT def_triangle
> we will find
> number of corner j of edge i given
>
> and i understand from that definition the following
>
> edge UG-trianglecorner dune-triangle-corner
> ---- ------ ----------
> 0 (0,1) (1,2)
> 1 (1,2) (2,0)
> 2 (2,0) (0,1)
>
>
> we will see some mismatch here.. i dont know if it is something wrong
> from my interpretation..
>
> we can see similar mismatch for hehexahedron as well...
>
> now i am afraid if the reference numbering on dune page doesnt match the
> UG definition?
>
> what do you say ..
>
> cheers,
> sreejith
>
>
>
> On Thu, Jul 21, 2005 at 02:18:40PM +0200, Oliver Sander wrote:
>> Hallo Sreejith!
>> Hmm, gute Frage! The local coordinates of the UG-pyramid should be
>> the same as the Dune-pyramid. I did the drawing on the web-page,
>> but maybe I screwed it up? The definition is in ug-cvs/gm/elements.c.
>> Or maybe the
>>
>> static DOUBLE_VECTOR_3D LMP_Pyramid = {0.5, 0.5,0.33333333333333333};
>>
>> is wrong? You never know. The final authority on these matters
>> is Stefan.
>>
>> Viel Gl?ck,
>> Oliver
>>
>> ************************************************************************
>> * Oliver Sander ** *
>> * Freie Universit?t Berlin ** email: sander at math.fu-berlin.de *
>> * Institut f?r Mathematik II ** phone: + 49 (30) 838 75217 *
>> * Arnimallee 2-6 ** fax : + 49 (30) 838 54977 *
>> * 14195 Berlin, Germany ** URL : www.math.fu-berlin.de/~sander *
>> ************************************************************************
>>
>> On Thu, 21 Jul 2005, Sreejith Pulloor Kuttanikkad wrote:
>>
>>>
>>> Hi Oliver,
>>>
>>> i was going through the "shapes.c" file in ug-cvs/gm/ directory and
>>> found that the local midpoint of the pyramid given is
>>>
>>> static DOUBLE_VECTOR_3D LMP_Pyramid = {0.5, 0.5,0.33333333333333333};
>>>
>>> but if we use the reference pyramid given in the dune webpage the local
>>> midpoint will be at {0.4,0.4,0.2}
>>>
>>> so my question is if the local coordinates of ug-pyramid is different from
>>> that of dune-pyramid?
>>> because i would like to copy the shape functions for the pyramid given in
>>> shapes.c to dune.
>>>
>>> gru?
>>> sreejith
>>>
>>> --
>>> Sreejith Pulloor Kuttanikkad
>>> Interdisciplinary Centre for Scientific Computing
>>> Ruprecht-Karls-University of Heidelberg
>>> Im Neuenheimer Feld-368
>>> 69120,Heidelberg,Germany
>>> ------------------------------------------------
>>> Ph:+49-06221-545689/544412(Off)
>>> :+49-017624228904(Mob)
>>> http://hal.iwr.uni-heidelberg.de/~sreejith/
>>> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>>>
>
>
> --
> Sreejith Pulloor Kuttanikkad
> Interdisciplinary Centre for Scientific Computing
> Ruprecht-Karls-University of Heidelberg
> Room:009, Im Neuenheimer Feld-348
> 69120,Heidelberg,Germany
> ------------------------------------------------
> Ph:+49-06221-545689/544412(Off)
> :+49-017624228904(Mob)
> http://hal.iwr.uni-heidelberg.de/~sreejith/
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
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