[Svensen]

Hi, I'm trying to implement a precise viscosity model from experimental measurements.

I've created a folder "Spline" and two files "Spline.C" and "Spline.H".
I've redefined calcNu() method in the following was:

Foam::tmp<Foam::volScalarField>
Foam::viscosityModels::Spline::calcNu() const
{
    volScalarField strain = strainRate();
     volScalarField nu = strain;
     
//for each element of a field
     for (unsigned i=0; i<strain.size(); i++){
         double n = strain[i]; //get a strain-rate
    
        const double dn = 250/sizeof(visc);
        n /= dn; //scale it to match an index of array
    
/*visc array includes 2000 values of measured viscosity*/
        unsigned x1 = floor(n);
        if (x1 < 1) x1 = 0; //check minimum value
        if (x1 >= sizeof(visc)) x1 = sizeof(visc)-2; //check maximum value
        
        unsigned x2 = x1 + 1;
    
        if (x1 != x2){
            double y1 = visc[x1];
            double y2 = visc[x2];
        
            double k = y2 - y1; //linear interpolation
            double b = x2*y1 - x1*y2;
        
            nu[i] = k*n + b;
        }
        else{
            nu[i] = visc[x1];
        }
     }
    
    return nu;
}

It compiles with no error, however after start of pimpleFoam it exits with the following log:

#0  Foam::error::printStack(Foam::Ostream&) at ??:?
#1  Foam::sigFpe::sigHandler(int) at ??:?
#2  ? in "/lib/x86_64-linux-gnu/libc.so.6"
#3  Foam::viscosityModels::Spline::calcNu() const at ??:?
#4  Foam::viscosityModels::Spline::Spline(Foam::word const&, Foam::dictionary const&, Foam::GeometricField<Foam::Vector<double>, Foam::fvPatchField, Foam::volMesh> const&, Foam::GeometricField<double, Foam::fvsPatchField, Foam::surfaceMesh> const&) at ??:?
#5  Foam::viscosityModel::adddictionaryConstructorToTable<Foam::viscosityModels::Spline>::New(Foam::word const&, Foam::dictionary const&, Foam::GeometricField<Foam::Vector<double>, Foam::fvPatchField, Foam::volMesh> const&, Foam::GeometricField<double, Foam::fvsPatchField, Foam::surfaceMesh> const&) at ??:?
#6  Foam::viscosityModel::New(Foam::word const&, Foam::dictionary const&, Foam::GeometricField<Foam::Vector<double>, Foam::fvPatchField, Foam::volMesh> const&, Foam::GeometricField<double, Foam::fvsPatchField, Foam::surfaceMesh> const&) at ??:?
#7  Foam::singlePhaseTransportModel::singlePhaseTransportModel(Foam::GeometricField<Foam::Vector<double>, Foam::fvPatchField, Foam::volMesh> const&, Foam::GeometricField<double, Foam::fvsPatchField, Foam::surfaceMesh> const&) at ??:?
#8  ? at ??:?
#9  __libc_start_main in "/lib/x86_64-linux-gnu/libc.so.6"
#10  ? at ??:?

What can be wrong with my code ?