[Dune] UG grid - limit on grid size?

[Oliver Sander]

Hm, interesting.  I have never seen this error message before.

What do you mean by 128x128x32x6 elements?

How much ram does your machine have?

Are you using the StructuredGridFactory?  Can you please file a bug
with a small test program so this doesn't get lost?

Thanks,
Oliver

Am 05.10.2011 15:07, schrieb Eike Mueller:
> Hi Oliver,
>
> this works, thanks a lot! After recompiling UG I can go up to
> 64x64x16x6, but if I try 128x128x32x6 (~ 2^22, but again, it's a serial
> run) I now get this:
>
> ERROR in InsertElement: ==> NdElPtrArray_GetMemAndCheckIDs( ) ERROR: No
> memory for MGNDELEMBLK(theMG,j)
> ERROR in InsertElement: ERROR by calling NdElPtrArray_GetMemAndCheckIDs()
> terminate called after throwing an instance of 'Dune::GridError'
>
> I tried increasing the heap size in the uggrid construction
>
> uggrid = new Dune::UGGrid<3>(10000);
>
> but I still get the same error message.
>
> Cheers,
>
> Eike
>
> Oliver Sander wrote:
>> Hi Eike!
>> This is a known problem. Please see the FAQ entry 4.2 on the dune
>> homepage
>> for an explanation and a workaround.
>> Cheers,
>> Oliver
>>
>> Am 05.10.2011 14:23, schrieb Eike Mueller:
>>> Dear Dune-list,
>>>
>>> I've used the UG grid factory to construct a UG grid on spherical shell
>>> like this [1], basically following the instructions in [2]. It all works
>>> fine, but fails (or rather hangs) once my grid reaches a certain size (I
>>> found that if the number of elements is 25x25x25x6 = 93750 it's ok, but
>>> for 26x26x26x6 = 105456 it fails). The number of nodes is about the same
>>> as the number of elements. I do not get a runtime error message, but it
>>> just hangs in
>>>
>>> uggrid = new Dune::UGGrid<3>;
>>> uggrid = factory.createGrid();
>>>
>>> Now, I might be getting the memory allocation wrong (I've tried passing
>>> a larger heapsize to to Dune::UGGrid<3> constructor), but I also saw
>>> this discussion here [3] saying that there are limits on the size of the
>>> UG grid that can be constructed (I do not compile with -DNDEBUG and this
>>> is a serial run and from how I understand it the limit should be 2^32
>>> elements in serial runs?).
>>>
>>> Basically, I've got a class called Cubedsphere, which has the private
>>> data field
>>>
>>> Dune::GridFactory<Dune::UGGrid<3>> factory;
>>> Dune::UGGrid<3>* uggrid;
>>>
>>> In the constructor I generate my grid vertices (I know the exact
>>> expressions for the positions, so don't need to read them from file) by
>>> first calling
>>>
>>> factory.insertVertex(vertex);
>>>
>>> for all vertices and storing their ids and positions (both as unsigned
>>> ints) in a lookup table and then generating the elements from the
>>> entries in the lookup table with
>>>
>>> factory.insertElement(cube,vertices);
>>>
>>> When all this is done I call
>>>
>>> uggrid = new Dune::UGGrid<3>;
>>> uggrid = factory.createGrid();
>>>
>>> in the constructor and the class also has a method
>>>
>>> Dune::UGGrid<3>* getUGGrid() { return uggrid; };
>>>
>>> for returning a reference to the uggrid pointer.
>>>
>>>
>>>
>>> Thank you very much for any help,
>>>
>>> Eike
>>>
>>>
>>>
>>> [1] http://people.bath.ac.uk/em459/dune.html
>>> [2]
>>> http://www.dune-project.org/doc/doxygen/html/classDune_1_1GridFactory_3_01UGGrid_3_01dimworld_01_4_01_4.html
>>>
>>>
>>> [3]
>>> http://www.dune-project.org/flyspray/index.php?do=details&task_id=250#comment2700
>>>
>>>
>>>
>>> _______________________________________________
>>> Dune mailing list
>>> Dune at dune-project.org
>>> http://lists.dune-project.org/mailman/listinfo/dune
>>
>