Metoda parabole - Minimum kod jednodimenzionih promjenjivih

function [xout, yout] = parabola(f, sstart, eend, e)
    x = [];
    x(1) = sstart;
    x(3) = eend;
    x(2) = (x(1) + x(3)) / 2;

    while true
        % Rjesavam sistem jednacina sa linsolve(), mada kontam da je bolje rucno
        mata = [
            1 x(1) x(1)^2;
            1 x(2) x(2)^2;
            1 x(3) x(3)^2;
        ];
        matb = [f(x(1)); f(x(2)); f(x(3))];
        sol = linsolve(mata, matb);
        a = sol(1);
        b = sol(2);
        c = sol(3);

        % Racunam Xopt
        % y(x)' = 0 => b + 2cx = 0 => x = -b / 2c
        x(4) = -b/(2*c);
        xopt = x(4);

        % Izbacujem najgoru vrijednost i ostavljam tri najbolje
        [val index] = sort([f(x(1)) f(x(2)) f(x(3)) f(x(4))]);
        x = [x(index(1)) x(index(2)) x(index(3))];

        % Improvizujem do-while
        if abs(f(xopt) - (a + b*xopt + c*xopt^2)) < e
            break;
        end;
    end

    xout = xopt;
    yout = f(xopt);
end