I am getting 'can not be used as a function error" in C++ when using for loop to calculate yc : I am calculating NACA 4 digit airfoil coordinates using C++. In this code i used armadillo library's linspace function to divide x into linearly spaced points. When i use for loop to calculate yc's value for each x's value I get error "yc" can not be used as function. Thanks for helping.

    #include<iostream>
    #include<armadillo>
    #include<vector>

    using namespace std;
    using namespace arma;
    int main()
    {
    
        float a[3];
        float c;
        int gp = 100;
    
        cout << "Please Enter NACA 4 digits" << endl;
        cout << "Please Enter 1st digit" << endl;
        cin >> a[0] ;
        cout << "Please Enter 2nd digit" << endl;
        cin >> a[1] ;
        cout << "Please Enter last 2 digits" << endl;
        cin >> a[2] ;
        cout << "Please Enter Chord Length" << endl;
        cin >> c;
    
        float m=(a[0]*c)/100;
        float p=(a[1]*c)/10;
        float t=(a[2]*c)/100;
    
        cout << m << endl;
        cout << p << endl;
        cout << t << endl;
        vec x = linspace<vec>(0, c, gp);
        float yc;
        for(int i=0;i<gp;++i)
    
            {
                if (x(i) = 0 && x(i) <= p){
                yc(i) = (m/(p*p))*((2*p*(x(i)))-(x(i)*x(i)));
            }
                if (x(i) > p && x(i) <= c) {
                yc(i) =(m/((1-p)*(1-p)))*((1-(2*p))+(2*p*x(i))-(x(i)*x(i)));
            }
            }
        cout<< yc <<endl;
    return 0;
    }



