CFD Online Discussion Forums - One dimensional array in OF21(Segmentation fault (core dumped))

CFD Online Discussion Forums (https://www.cfd-online.com/Forums/)

- OpenFOAM Programming & Development (https://www.cfd-online.com/Forums/openfoam-programming-development/)

- - One dimensional array in OF21(Segmentation fault (core dumped)) (https://www.cfd-online.com/Forums/openfoam-programming-development/246759-one-dimensional-array-of21-segmentation-fault-core-dumped.html)

One dimensional array in OF21(Segmentation fault (core dumped))

Hello all
I am defining a one dimensional parameter which has 2 million elements;

Code:

   int nCounter = U.size();

   Info << "1" << endl;

   scalar AAAA[nCounter];

   for(int i=0; i<nCounter; i++) { AAAA[i] = 0;}

and it gives this error;

Code:

1

Segmentation fault (core dumped)

why I got this error in OF21?

I afraid that maybe i counter goes beyond the limits so I change it to

Code:

for(int i=1 i<100; i++) { AAAA[i] = 0;}

but still it gives me the same error. Why?

Thanks,
Farzad

Quote:

Originally Posted by farzadmech (Post 841591)

Hello all
I am defining a one dimensional parameter which has 2 million elements;

Code:

   int nCounter = U.size();

   Info << "1" << endl;

   scalar AAAA[nCounter];

   for(int i=0; i<nCounter; i++) { AAAA[i] = 0;}

and it gives this error;

Code:

1

Segmentation fault (core dumped)

why I got this error in OF21?

I don't understand the source of your error, but there is no reason to be using raw C arrays instead of an OpenFOAM list or even a std vector. Give the following a try:

Code:

scalarField AAA(U.size());



for (label i=0; i < AAA.size(); ++i)

{

    AAA[i] = 0;

}

If you actually want to initialize with zero (and not just demonstrate the segfault), it would actually make sense to do that immediately on construction:

Code:

scalarField AAA(U.size(), Zero);

Thanks a lot for your advice. I did it like this as you said and it works;

Code:

   int nCounter = U.size();

   scalarField AAA(nCounter);

and since I need it to set zero every time step, I set it zero like this every time step;

Code:



for(int i=0; i<nCounter; i++) 

{AAA[i] = 0;}

Is there any easier way to put it zero every time step?

Thanks,
Farzad

Quote:

Originally Posted by olesen (Post 841623)

I don't understand the source of your error, but there is no reason to be using raw C arrays instead of an OpenFOAM list or even a std vector. Give the following a try:

Code:

scalarField AAA(U.size());



for (label i=0; i < AAA.size(); ++i)

{

    AAA[i] = 0;

}

If you actually want to initialize with zero (and not just demonstrate the segfault), it would actually make sense to do that immediately on construction:

Code:

scalarField AAA(U.size(), Zero);

Quote:

Originally Posted by farzadmech (Post 841663)

Thanks a lot for your advice. I did it like this as you said and it works;

Code:

   int nCounter = U.size();

   scalarField AAA(nCounter);

and since I need it to set zero every time step, I set it zero like this every time step;

Code:



for(int i=0; i<nCounter; i++) 

{AAA[i] = 0;}

Is there any easier way to put it zero every time step?

Thanks,
Farzad

You can either use the vectorized method to make the for loop obsolete (but I think the compiler automatically using SIMD and might be that an overloaded operator[] will prohibit this operation) or I know for the GeometricField<T> class there is an overloaded operator= which sets the whole Field with a particular value. Since GeometricField is inhereting from Field class (if you go for Field<scalar>) I think there should be something similiar

Code:

AAA[:] = 0 //vectorized



// works at least for GeometricField<T>

AAA = dimensionedScalar(dimless, 0.0) //sets .ref and .boundaryFieldRed to 0