[TRNSYS-users] numerical solution in new type with C++

[iris.reichenbach at iwtt.tu-freiberg.de]

Dear all,
Thanks again to Marcello and David, your suggestions helped. I'm stuck  
now at another, related problem. I inserted the following lines into  
the header file:

extern "C" __declspec(dllimport) void	_cdecl  
TRNSYSFUNCTIONS_mp_SETNUMERICALDERIVATIVE(int, double);
extern "C" __declspec(dllimport) double _cdecl  
TRNSYSFUNCTIONS_mp_GETNUMERICALSOLUTION(int);
extern "C" __declspec(dllimport) double _cdecl  
TRNSYSFUNCTIONS_mp_TAUALPHA(int,double,double,double,double,double);

Now I get the following error message when I try to compile:
error LNK2019: Verweis auf nicht aufgelöstes externes Symbol  
"__imp__TRNSYSFUNCTIONS_mp_SETNUMERICALDERIVATIVE" in Funktion  
"_TYPE236".
1>Type236.obj : error LNK2019: Verweis auf nicht aufgelöstes externes  
Symbol "__imp__TRNSYSFUNCTIONS_mp_TAUALPHA" in Funktion "_TYPE236".


(This translates to something like unresolved external symbol) Note  
that I addded lines for SetNumericalDerivative, GetNumericalDerivative  
and TauAlpha, but get the error only for two of these lines, even  
though I'm using all three functions. Are these possibly not  
referenced in the dll or is there an error in my changes to the h  
file? Any help is appreciated.
Thanks,
Iris


Zitat von marcello.caciolo at cofelyaxima-gdfsuez.com:

> Dear Iris,
>
> I am not an expert of C++ programming, but I think that, in order to  
> be consistent with Fortran declaration of these functions, you  
> should just declare the functions in the .h header file as :
>
> extern "C" __declspec(dllimport) void _cdecl  
> TRNSYSFUNCTIONS_mp_SETNUMERICALDERIVATIVE(int, double);
> extern "C" __declspec(dllimport) double _cdecl  
> TRNSYSFUNCTIONS_mp_GETNUMERICALSOLUTION(int);
>
> and after
>
> #define SetNumericalDerivative TRNSYSFUNCTIONS_mp_SETNUMERICALDERIVATIVE
> #define GetNumericalSolution TRNSYSFUNCTIONS_mp_GETNUMERICALSOLUTION
>
>
> Hope this helps!
>
> Marcello Caciolo
> Responsable Outils et Méthodes d'Analyse Energétique
>
>
> Cellule Efficacité Energétique et Environnementale - Pôle Projets et  
> Réalisations
> 46 Boulevard de la Prairie au Duc
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> marcello.caciolo at cofelyaxima-gdfsuez.com
> Pensez à l'environnement avant d'imprimer ce message
>
>
>
> -----Message d'origine-----
> De : TRNSYS-users  
> [mailto:trnsys-users-bounces at lists.onebuilding.org] De la part de  
> Iris Reichenbach
> Envoyé : jeudi 28 août 2014 13:04
> À : TRNSYS users mailing list at OneBuilding.org
> Objet : Re: [TRNSYS-users] numerical solution in new type with C++
>
> Dear David,
>
> Thank you for your response, I tried to do this. However, I have no  
> idea what I am doing here.
> As a first try I just added the lines
> extern "C" __declspec(dllimport) double _cdecl  
> TRNSYSFUNCTIONS_mp_SETNUMERICALDERIVATIVE(void);
> extern "C" __declspec(dllimport) double _cdecl  
> TRNSYSFUNCTIONS_mp_GETNUMERICALSOLUTION(void);
> and
> #define SetNumericalDerivative TRNSYSFUNCTIONS_mp_SETNUMERICALDERIVATIVE
> #define GetNumericalSolution TRNSYSFUNCTIONS_mp_GETNUMERICALSOLUTION
> to the TRNSYS.h file. However, this did not work. I also noticed  
> that there is a getNumericalSolver in the .h file, I'd think that  
> implies that there should be a numerical solver accessible for C++?
> Also, I have the same problem for the function Tau_Alpha, I also  
> can't use it.
> Could someone give me any more hints on how to either change the .h  
> file or use another way of finding the numerical solutions?
> Thanks in advance,
> Iris
>
>
>
> Am 27.08.2014 17:46, schrieb David BRADLEY:
>> Iris,
>>  I am no expert in writing C++ components (in fact I have never tried
>> it). My guess, however, is that you will need to modify the TRNSYS.h
>> file to make sure that the setNumericalDerivative() and
>> getNumericalSolution() functions are actually defined in there.
>> Kind regards,
>>  David
>>
>>
>> On 8/27/2014 07:52, Iris Reichenbach wrote:
>>> Dear fellow TRNSYS users,
>>> I have the following problem. I'm trying to write a new type for
>>> TRNSYS in C++, which involves the numerical solution of differential
>>> equations. Usually, SetNumericalDerivative is used to set the
>>> numerical derivatives and then GetNumericalSolution is used to obtain
>>> the solution of the differential equation. However, when trying to
>>> compile my code the compiler gives the following error: "error
>>> C3861:  "getNumericalSolution": Bezeichner wurde nicht gefunden."
>>> That is, it can't find the identifier getNumericalSolution.
>>> I also tried to instead use the older form and write dtdt[i] = x,
>>> instead of SetNumericalDerivative(i,x), but here I got the error
>>> message "error C2109: Index erfordert ein Array oder einen Zeigertyp"
>>> (that is index requires an array or a pointer).
>>> I  use the project CPP-Mvs2003, which is included in
>>> TRNSYS/Compilers, so it has access to TRNSYS.h and TRNDll.lib, and I
>>> also successfully used my setup to generate another custom type,
>>> albeit without any numerical solution.
>>> So my question is: how can I solve numerical equations with a type
>>> written in C++? How do I set the derivatives and how do I access the
>>> solutions? Do GetNumericalSolution/SetNumericalDerivative not work
>>> with C++ (I didn't find them in TRNSYS.h) and if so, what do I use
>>> instead?
>>> Thanks in advance for any pointers!
>>> Cheers,
>>> Iris
>>> _______________________________________________
>>> TRNSYS-users mailing list
>>> TRNSYS-users at lists.onebuilding.org
>>> http://lists.onebuilding.org/listinfo.cgi/trnsys-users-onebuilding.or
>>> g