I'm having trouble initializin
 

I'm having trouble initializing some pointers. The code compiles fine, but when I run my case (which, at the moment is very basic) and run my createFields.H file, it says that I'm trying to assign a value to a null reference: is there a way of initializing the pointer list to non-null values?

This is part of my createFields.H file:

const N_Bins = 6;
PtrList<volvectorfield> U_;
U_.setSize(N_Bins);

{
std::stringstream converter;
for (int i = 0; i < N_Bins; i++)
{
converter.str("");
converter << (i+1);
word phaseNumber = word(converter.str());

volVectorField Utemp(
IOobject
(
"Ua"
mesh.time().timeName(),
mesh,
IOobject::READ_IF_PRESENT,
IOobject::AUTO_WRITE
),
Ua
);

U_[i] = Utemp;
}
}

This is the error that is generated when I run the case:

--> FOAM FATAL ERROR : hanging pointer, cannot dereference#0 Foam::error::printStack(Foam:http://www.cfd-online.com/OpenFOAM_D...part/proud.gifstream&)
#1 Foam::error::abort()
#2 main
#3 __libc_start_main
#4 __gxx_personality_v0


From function PtrList::operator[]
in file /usr/local/OpenFOAM/OpenFOAM-1.4/src/OpenFOAM/lnInclude/PtrListI.H at line 92.

Hi, Just a thought... maybe
 

Hi,

Just a thought... maybe PtrList starts from index "1" and not index "0".... not sure, but that error message seems to kind of point to that.

Have a nice day!

Philippose

Philippose, I've tried maki
 

Philippose,

I've tried making a loop from i=1 -> N_Bins, but I get the same error:

--> FOAM FATAL ERROR : hanging pointer, cannot dereference#0 Foam::error::printStack(Foam:http://www.cfd-online.com/OpenFOAM_D...part/proud.gifstream&)
#1 Foam::error::abort()
#2 main
#3 __libc_start_main
#4 __gxx_personality_v0


From function PtrList::operator[]
in file /usr/local/OpenFOAM/OpenFOAM-1.4/src/OpenFOAM/lnInclude/PtrListI.H at line 92.

I have a suspision that it's making a list of pointers of null values - and I tried to make a pointer array of volVectorFields, declare the loop, then pass the variables into the PtrList, but this also did not work. Thanks for the input either way - it was a worthy idea to check.

Hi Mateusz, maybe if you tr
 

Hi Mateusz,

maybe if you try to do make the loop from i=0 to N_binc-1 you'll fix the issue, I don't know if this is the problem, but it seems something about 0 value

Hope this helps

Regards

Francesco

Hi again, I was checking up
 

Hi again,

I was checking up in the Doxygen help system online, and found the following....

T & operator[](const label)[inline]

Return element reference.


Now.... the operator [] returns a reference to the element.... which means, it can be used on the RHS of an assignment... not on the LHS.

As far as I can see, I don't think you can use this to actually assign elements to the pointer list... you need to use the following member function of the PtrList class:

U_.set(i,Utemp)

"set" is the member function which actually lets you fill the list.

Hope this helps :-)!

Philippose

Actually... this is exactly wh
 

Actually... this is exactly what I was looking for - I changed the code and the program (with fixing some other... elementary... errors) ran perfectly. Thank you for the help!

Hello, I have a problem on this issue.

It works well for me. I use the volVectorField's in equations using U_[0], U_[1], etc.
However, when the runtime is complete, it does not output the resulting vectorfields although it is mentioned AUTO_WRITE.

why would that be the case?

Hi MikeP,

I am having the same problem that you mentioned. Have you figured out why it is like that?

If yes, could you show me how to solve this problem.

Terrence.

Can you post up your code and a case if possible?