[sina_mech]

Hi,

I'm trying to compile a solver. I have several functions that those functions want to access some mesh data, and I would like to keep those functions in separate C files, and having access in main C file via header files. Please see "testme.C" below! I get errors, cuase I can't access to 'vector', 'label', 'mesh', and etc. How can I fix that?

Example (I know the purpose of the function doesn't make sense ... but it's just an example!)

// testme.C file
double TestMe(std::vector <double> & myvec)
{
	vector myPoint(1.0, 1.0, 1.0);
	label myCell = mesh.findCell(myPoint);
	
	double u_here = U[myCell].component(0);
	
	return u_here;
}

// testme.h file
double TestMe(std::vector <double> & myvec);

// mySolver.C file


...
int main(int argc, char *argv[])
{
 ...
 
	std::vector <double> myvec;
	double x_com = TestMe (myvec);
	
	....
	....
	
}

[sina_mech]

Any suggestions would be really helpful

[hk318i]

Your code has some major issues, I will try to highlight the main problems;

• The data types like label, scalar and vector are not available because the header files are not included.
• The variable ``mesh`` is not available within the function scope. You may need to pass a reference to it.
• You are mixing between std C++ data types and OpenFOAM which is not a good practice and could cause some problems later.
• Creating functions or classes and compile them directory with a solver is not OpenFOAM style.
• OpenFOAM has few utilities which create header, source and application files which follow OpenFOAM style. (foamNew, foamNewBC, foamNewSource, foamNewApp, foamNewCase, foamNewTemplate)

Here is a minimal example,

//fun.H
#ifndef fun_H
#define fun_H

#include "scalar.H"
#include "vector.H"

namespace Foam
{
    vector TestMe(const vector& myvec);

}
#endif

//fun.C
#include "fun.H"

Foam::vector Foam::TestMe(const vector& myvec)
{
    Info<< "Hello from TestMe" << endl;
    Info<< "vector: " << myvec << endl;
    Info<< "vectorXcmpt: " << myvec.component(0) << endl;
    Info<< "vectorYcmpt: " << myvec.component(1) << endl;
    Info<< "vectorZcmpt: " << myvec.component(2) << endl;
    return myvec;
}

//exApp.C
#include "fun.H"

using namespace Foam;

int main(int argc, char *argv[])
{
    vector A(1,2,3);
    vector B(4,5,6);
    vector a = TestMe(A);
    vector b = TestMe(B);
    Info<< "Hello from the main()" << endl;
    Info<< "vector a: "  << a << endl;
    Info<< "vector b: "  << b << endl;
    return 0;
}

//Make/files
fun.C
exApp.C

EXE = $(FOAM_USER_APPBIN)/exApp

and you can leave Make/options empty for this case but for a basic case you may need something like this

//Make/files
EXE_INC = \
    -I$(LIB_SRC)/finiteVolume/lnInclude \
    -I$(LIB_SRC)/meshTools/lnInclude

EXE_LIBS = \
    -lfiniteVolume \
    -lmeshTools

I know it looks very long for minimal example but that is how C++ works.

Best wishes,
Hassan

[sina_mech]

Originally Posted by hk318i

Your code has some major issues, I will try to highlight the main problems;

• The data types like label, scalar and vector are not available because the header files are not included.
• The variable ``mesh`` is not available within the function scope. You may need to pass a reference to it.
• You are mixing between std C++ data types and OpenFOAM which is not a good practice and could cause some problems later.
• Creating functions or classes and compile them directory with a solver is not OpenFOAM style.
• OpenFOAM has few utilities which create header, source and application files which follow OpenFOAM style. (foamNew, foamNewBC, foamNewSource, foamNewApp, foamNewCase, foamNewTemplate)

Here is a minimal example,

//fun.H
#ifndef fun_H
#define fun_H

#include "scalar.H"
#include "vector.H"

namespace Foam
{
    vector TestMe(const vector& myvec);

}
#endif

//fun.C
#include "fun.H"

Foam::vector Foam::TestMe(const vector& myvec)
{
    Info<< "Hello from TestMe" << endl;
    Info<< "vector: " << myvec << endl;
    Info<< "vectorXcmpt: " << myvec.component(0) << endl;
    Info<< "vectorYcmpt: " << myvec.component(1) << endl;
    Info<< "vectorZcmpt: " << myvec.component(2) << endl;
    return myvec;
}

//exApp.C
#include "fun.H"

using namespace Foam;

int main(int argc, char *argv[])
{
    vector A(1,2,3);
    vector B(4,5,6);
    vector a = TestMe(A);
    vector b = TestMe(B);
    Info<< "Hello from the main()" << endl;
    Info<< "vector a: "  << a << endl;
    Info<< "vector b: "  << b << endl;
    return 0;
}

//Make/files
fun.C
exApp.C

EXE = $(FOAM_USER_APPBIN)/exApp

and you can leave Make/options empty for this case but for a basic case you may need something like this

//Make/files
EXE_INC = \
    -I$(LIB_SRC)/finiteVolume/lnInclude \
    -I$(LIB_SRC)/meshTools/lnInclude

EXE_LIBS = \
    -lfiniteVolume \
    -lmeshTools

I know it looks very long for minimal example but that is how C++ works.

Best wishes,
Hassan

Hi Hassan,

Thank you for your reply I know i would be better to stick to openFoam's protocols, but in a case, I tried this out, and seems to be working:

//myOwnCFile.C

#include "fvMesh.H"
#include "fvCFD.H"

void MyFunction(std::vector<double> & test, fvMesh const& mesh, vectorField & U)
...

In the function above, I use mesh and velocity field (U) as variables by passing a reference to it. What do you think about it?

[hk318i]

It is up to you to use std C++ or not. If you are passing a value by refrence and not planning to change the variable within the function or class, use ``const`` identifier.

void MyFunction(const std::vector<double>& test, const fvMesh& mesh, const vectorField& U)
{
    ... ....
}

[wangchengan2003]

Dear Hassan,

I want to create some functions in the solver. I have tested the code you proposed. They are correct perfectly.

I just want to replace the fun.H file by

template<class CloudType>
inline const Foam::tmp<Foam::volVectorField>
Foam::KinematicCloud<CloudType>::UPar() const
{
    tmp<volVectorField> tUPar
    (
        volVectorField::New
        (
            this->name() + ":UPar",
            mesh_,
            dimensionedVector(dimVelocity, vector(0,0,0)),
            extrapolatedCalculatedFvPatchVectorField::typeName
        )
    );


    volVectorField& UPar = tUPar.ref();
    forAllConstIter(typename KinematicCloud<CloudType>, *this, iter)
    {
        const parcelType& p = iter();
        const label celli = p.cell();
        UPar[celli] += (p.U())/(p.nParticle());
    }
    UPar.primitiveFieldRef() /= 1;//mesh_.V();
    UPar.correctBoundaryConditions();

    return tUPar;
}



  
template<class CloudType>
inline const Foam::tmp<Foam::volScalarField>
Foam::KinematicCloud<CloudType>::SumPar() const
{
    tmp<volScalarField> tSumPar
    (
        volScalarField::New
        (
            this->name() + ":SumPar",
            mesh_,
            dimensionedScalar(dimless, 0),
            extrapolatedCalculatedFvPatchScalarField::typeName
        )
    );


    volScalarField& SumPar = tSumPar.ref();
    forAllConstIter(typename KinematicCloud<CloudType>, *this, iter)
    {
        const parcelType& p = iter();
        const label celli = p.cell();
        SumPar[celli] += p.nParticle();
    
    }

    SumPar.primitiveFieldRef() /= 1;//mesh_.V();
    SumPar.correctBoundaryConditions();

    return tSumPar;
}

from Lagrangian data - particle velocity post processing

such as

//fun.H
#ifndef fun_H
#define fun_H


template<class CloudType>
inline const Foam::tmp<Foam::volVectorField>
Foam::KinematicCloud<CloudType>::UPar() const
{
    tmp<volVectorField> tUPar
    (
        volVectorField::New
        (
            this->name() + ":UPar",
            mesh_,
            dimensionedVector(dimVelocity, vector(0,0,0)),
            extrapolatedCalculatedFvPatchVectorField::typeName
        )
    );


    volVectorField& UPar = tUPar.ref();
    forAllConstIter(typename KinematicCloud<CloudType>, *this, iter)
    {
        const parcelType& p = iter();
        const label celli = p.cell();
        UPar[celli] += (p.U())/(p.nParticle());
    }
    UPar.primitiveFieldRef() /= 1;//mesh_.V();
    UPar.correctBoundaryConditions();

    return tUPar;
}



  
template<class CloudType>
inline const Foam::tmp<Foam::volScalarField>
Foam::KinematicCloud<CloudType>::SumPar() const
{
    tmp<volScalarField> tSumPar
    (
        volScalarField::New
        (
            this->name() + ":SumPar",
            mesh_,
            dimensionedScalar(dimless, 0),
            extrapolatedCalculatedFvPatchScalarField::typeName
        )
    );


    volScalarField& SumPar = tSumPar.ref();
    forAllConstIter(typename KinematicCloud<CloudType>, *this, iter)
    {
        const parcelType& p = iter();
        const label celli = p.cell();
        SumPar[celli] += p.nParticle();
    
    }

    SumPar.primitiveFieldRef() /= 1;//mesh_.V();
    SumPar.correctBoundaryConditions();

    return tSumPar;
}


#endif

And I don't use fun.C file. After compiling, there are some mistakes;

fun.H:16:41: error: no ‘const Foam::tmp<Foam::GeometricField<Foam::Vector<double>, Foam::fvPatchField, Foam::volMesh> > Foam::KinematicCloud<CloudType>::UPar() const’ member function declared in class ‘Foam::KinematicCloud<CloudType>’
 Foam::KinematicCloud<CloudType>::UPar() const
                                         ^
fun.H:48:43: error: no ‘const Foam::tmp<Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> > Foam::KinematicCloud<CloudType>::SumPar() const’ member function declared in class ‘Foam::KinematicCloud<CloudType>’
 Foam::KinematicCloud<CloudType>::SumPar() const

I think I need to add some codes in fun.H. Could you give me some suggestions?

Best regards,

Chengan