Function neg_rosen

dlib/test/optimization.cpp:100–104

negative of Rosenbrock's function. minimum at (1,1)

    // negative of Rosenbrock's function.  minimum at (1,1)
    double neg_rosen ( const matrix<double,2,1>& x)
    {
        ++total_count;
        return -(100*pow(x(1) - x(0)*x(0),2) + pow(1 - x(0),2));
    }

    matrix<double,2,1> der_neg_rosen ( const matrix<double,2,1>& x)
    {