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

[Iris Reichenbach]

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