[TRNSYS-users] using storage c++ type

[knut.erik.enerstvedt at niva.no]

Wouter,

I have compiled and tried your C++ component, and it runs without any
"invalid floating point error" on my machine. I use the Microsoft Visual
C++ 2008 Express Edition compiler.

The Type doesn't quite work as you have explained, however. Instead of
adding 1 to the two stored variables for every timestep, it simply sets
them equal to 1 at each timestep. To add 1, write stored[0]+=1 instead of
stored[0]=+1.

I can not see any further errors in your code. By the way, do you know for
sure that you have declared the storage functions correctly in the
"TRNSYS.h" file? I don't think the pointer construction of "nitems" should
be a problem, as it works for me when I use &nitems directly as function
argument.

I hope this was helpful in some way...

Kind regards
Knut Erik Enerstvedt






                                                                           
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----- Message from Wouter Lumen <wouter.lumen at ugent.be> on Sat, 19 Apr 2008
19:50:13 +0200 -----
                                                                           
           To: trnsys-users at engr.wisc.edu                                  
                                                                           
      Subject: [TRNSYS-users] using storage c++ type                       
                                                                           

Dear trnsys users,

I'm having some troubles with using storage in my new c++ component.
Every time i run the component i get a "invalid floating point error".

I've have read about the possible causes of this error and i have narrowed
it down to a problem with storage.

I have attached a very simple sourcecode:
It reads in 2 numbers (getal1 and getal2) and puts them back out after
adding
a constant to them (in this case, double a and double b).

When i run this component and use hard coded values, such as 1 and 2
for a and b, the
component works flawless.

But when i use storage (as in the attached file), i get the error.
The storage is used in the following way:
Every timestep "1" is added to the stored variables.
So basically, now I add a larger, with timestep increasing, value to getal1
and getal2.

I have tried severall configurations when using the storage such as:
not using the info[12]>0 manipulations,
not using the setstorage at the end of the calculations,
using them both, etc etc...
Maybe the problem is in this, may be not...

Another possible cause (which i think is more likely), is that it has
something
to do with the pointerconstruction for "nitems":
int nitems=2;
int* pitems=&nitems;
double stored[2]={0,0};
so that pitems points to nitems.
This is done because the storage functions take an int* as argument
and not an int.

If anybody has any suggestions on what the problem could be, or could
modify
the sourcefile in a way that it should work. Please let me know.

Thank you very much.

Kind regards,

Wouter Lumen.







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