void readData(const string & filename, vector<double> & angleData, vector<double> & liftData) {
    ifstream inFS;
    double angle1; double lift1;
    //double angle2; double lift2;

    inFS.open(filename.c_str());

    if (!inFS.is_open()) {
        cout << "Error opening file";
        return;
    }
    while (!inFS.eof()) {
        inFS >> angle1;
        angleData.push_back(angle1);
        inFS >> lift1;
        liftData.push_back(lift1);
        inFS.ignore();
    }
    inFS.close();

    return;
}