[Arham]

Hi
I am working on a project to solve 17 ordinary differential equations. And later manipulating the data obtained from these equations.

The error says

error: no matching function for call to ‘pow(Foam::tmp<Foam::Field<int> >, int)’

and if I remove Cpmax from the Up function I get

error: no matching function for call to ‘pow(Foam::labelList&, int)’


I have used labelList Cp to store y[8] at different iterations. I have tried with float Cp[] as well but that somehow led to an infinite loop.

Can you help me by proposing an appropriate data type to store y[8] in Cp or a possible way to conver the data type to float so as to perform mathematical functions such as pow, tanh, sinh etc.
Or any way to perform mathematical functions to the data that we get.

Thank you

The main code is given below:

int main(int argc, char *argv[])
{
    argList::validArgs.append("ODESolver");
    argList args(argc, argv);

    // Create the ODE system
    testODE ode;

    dictionary dict;
    dict.add("solver", args[1]);

    // Create the selected ODE system solver
    autoPtr<ODESolver> odeSolver = ODESolver::New(ode, dict);

    // Initialise the ODE system fields
    scalar xStart = 0.0;
    scalarField yStart(ode.nEqns());
    for (label i=0; i<19; i++)  yStart[i] = 15977.4;
    for (label i=9; i<19; i++)  yStart[i] = 16391.7;
    
    
    // Print the evolution of the solution and the time-step
    scalarField dyStart(ode.nEqns());
    ode.derivatives(xStart, yStart, dyStart);

    scalarField y(yStart);

    scalar dxEst = 1;

    scalarField yMid(yStart);
    scalarField yFinal;
    
    labelList Cp[2300];
    labelList Cn[2300];
    
    Cp[0]=15977.4;
    Cn[0]=16391.7;
    
    for (label i=0; i<2300; i++)
    {
    
        scalar x = i;
        scalarField y(yMid);
        scalar xEnd = x + 1 ;

        odeSolver->relTol() = 1e-4;
        odeSolver->solve(x, xEnd, y, dxEst);
		
   	 Info << "Iteration Number :"<< i << endl;
   	 Info << " Cs (Anode) " << y[8] << endl;
   	 Info << " Cs (Cathode) "  << y[17] << endl;
    
    	 yMid = y;
    	 Cp[i+1] = y[8];
    	 
    	 
    }
    
    
    labelList Up[2300];
    labelList Un[2300];
    label Cpmax = 30357.07;
    
    for(label i=0; i<2300; i++)
    {
    
	Up[i] = (-4.656 + 88.669*pow((Cp[i])/Cpmax),2) ;
    
    }
    
    
    
    
    return 0;



}

[Arham]

I have figured it out by setting

Cp[i] = float (y[8]);

Thank you

[JBeilke]

Have you tried

Foam::pow()

[Arham]

Yes tried that as well

Test-ODE.C:576:43: error: expected primary-expression before ‘(’ token
 
 576 |          Up[i] = (-4.656 + 88.669*(::Foam(pow((Cp[i]/Cpmax),2)))

The '(' is sandwiched between pow and Foam.
Btw tried ::Foam inside pow as well.
Then I got

"Cp is not a member function of Foam".