[Dune] communication of dynamic vectors

[Martin Nolte]

Call me stupid, but I still don't know what Vector::value_type really is. And 
this information might or might not have a huge impact.

Best,

Martin

Martin

On 03/15/2012 12:48 AM, Fallahi Arya wrote:
> Hi Martin, Andreas and Christian,
>
> First thanks a lot for your quick replies and your guesses. Actually, I thought I was clear enough and have written the whole required things, but it seems I was wrong. Sorry for the disturbance. I thought maybe you already had faced with such an issue.
>
> As I mentioned in my first email, I receive error when the template "Vector" is set to "DynamicVector" and it runs ok when it is set to "FieldVector". Furthermore, I am using ALUGrid.
>
> The code compiles correctly and completely, so the error does not happen during the compilation. The error was returned by C++ during the runtime, exactly when the communication is to be fulfilled. I myself could actually understand nothing from the message, but if it may be helpful I will send it tomorrow morning, because I should run the code again to see the error.
>
> The reason I want to use "DynamicVector" is that the dimensions of the vector is found by a function at the very beginning of the code. So, although it never changes in the code, it can not be of type "const". That's the reason I am trying to use "DynamicVector" instead of "FieldVector" as the template parameter (referenced by "Vector"). Perhaps, the suggestion that the fixedsize is not true is the sort of the problem. I will check it again and let you know tomorrow, when I send you the error message.
>
> Thanks again for your support,
> Arya
>
>
>
> -----Original Message-----
> From: dune-bounces+arya.fallahi=psi.ch at dune-project.org on behalf of Martin Nolte
> Sent: Wed 3/14/2012 8:58 PM
> To: dune at dune-project.org
> Subject: Re: [Dune] communication of dynamic vectors
>
> Hi Arya,
>
> Sorry, but any answer to your request would be pure guess work. What kind of
> error message are you referring to (compiler error, runtime exception,
> assertion, undefined behavior, ...). Moreover, the code is absolutely useless,
> because you are not stating the template arguments. For example: What is Vector?
> Not to mention: What grid are you using?
>
> Maybe you could you even provide a simple example program and file a correct bug
> report? This would potentially allow us to reproduce the error and give you a
> helpful answer.
>
> Please note: Even writing such a reply takes a lot of time and DUNE' development
> team is rather small, its support team is even non-existent. If you want useful
> answers (unlike the one I just wrote), you might want to consider writing
> understandable or reproducible questions.
>
> Best,
>
> Martin
>
> On 03/14/2012 07:27 PM, arya fallahi wrote:
>> Dear Dune team,
>>
>> Recently, I have had a problem with the communication of variables with type
>> DynamicVector. I have the following communicator inside a code, which is written
>> in accordance with the Dune guide notes:
>>
>> template<classElementMapper, classVector>
>> classDataHandle: publicDune::CommDataHandleIF<DataHandle<ElementMapper,Vector>,
>> typenameVector::value_type>
>> {
>>
>> public:
>> typedeftypenameVector::value_typeDataType;
>> bool contains (int dim, int codim) const { return (codim==0); }
>> bool fixedsize (int dim, int codim) const {returntrue; }
>>
>> template<classEntityType>  size_t size (EntityType&  e) const { return(1); }
>>
>> template<classMessageBuffer, classEntityType>
>> void gather (MessageBuffer&  buff, const EntityType&  e) const
>> {
>> unsigned int globalElementIndex=elementMapper_.map(e);
>> buff.write(v_[globalElementIndex]);
>> }
>>
>> template<classMessageBuffer, classEntityType>
>> void scatter (MessageBuffer&  buff, const EntityType&  e, size_t n)
>> {
>> DataType x;
>> buff.read(x);
>> unsigned int globalElementIndex=elementMapper_.map(e);
>> v_[globalElementIndex] = x;
>> }
>>
>> DataHandle (const ElementMapper&  elementMapper, Vector&  v):
>> elementMapper_(elementMapper),v_(v){}
>>
>> private:
>> constElementMapper&  elementMapper_;
>> Vector&  v_;
>> };
>>
>> This works well when variables with type FieldVector
>> (Dune::FieldVector<double,6>) are going to be communicated. However, when I want
>> to communicate DynamicVector (Dune::DynamicVector<double>) data, the code stops
>> and I receive an error message. I believe the problem lies in the communication
>> part, since the code with DynamicVector works well on 1 processor. Do you have
>> any idea why such a thing happens? Have you previously faced with this problem?
>>
>> Best regards and thanks,
>>
>> Arya Fallahi,
>> Dr. sc. techn. ETH,
>> Computational Accelerator Scientist
>> Paul Scherrer Institute (PSI),
>> CH-5232 Villigen, Switzerland,
>> arya.fallahi at psi.ch<mailto:arya.fallahi at psi.ch>,
>> +41(0)56 310 50 17
>>
>>
>>
>>
>> _______________________________________________
>> Dune mailing list
>> Dune at dune-project.org
>> http://lists.dune-project.org/mailman/listinfo/dune
>

-- 
Dr. Martin Nolte <nolte at mathematik.uni-freiburg.de>

Universität Freiburg                                   phone: +49-761-203-5630
Abteilung für angewandte Mathematik                    fax:   +49-761-203-5632
Hermann-Herder-Straße 10
79104 Freiburg, Germany