% Define environment (functions, gradients etc...)
GivenEnv


% Point x0 = (0, 0)
% =========================================================================
point = 1;
x0 = [0, 0];
f = fun(x0(1), x0(2));
gf = grad_fun(x0(1), x0(2));
hf = hessian_fun(x0(1), x0(2));
ev = eig(hf);
fprintf('Initial point (%d, %d), f = %f, grad = [%f;%f], hessian = [%f %f ; %f %f]. Eigenvalues= [%f, %f], Can NOT use method\n', x0, f, gf, hf, ev);
disp(' ');


% Point x0 = (-1, 1)
% =========================================================================
point = 2;
x0 = [-1, 1];
point_str = "[" + x0(1) + ", " + x0(2) + "]";

f = fun(-1, 1);
gf = grad_fun(x0(1), x0(2));
hf = hessian_fun(x0(1), x0(2));
ev = eig(hf);
fprintf('Initial point (%d, %d), f = %f, grad = [%f;%f], hessian = [%f %f ; %f %f]. Eigenvalues= [%f, %f], Can NOT use method\n', x0, f, gf, hf, ev);
disp(' ');

% Point x0 = (1, -1)
% =========================================================================
point = 3;
x0 = [1, -1];
point_str = "[" + x0(1) + ", " + x0(2) + "]";

f = fun(-1, 1);
gf = grad_fun(x0(1), x0(2));
hf = hessian_fun(x0(1), x0(2));
ev = eig(hf);
fprintf('Initial point (%d, %d), f = %f, grad = [%f;%f], hessian = [%f %f ; %f %f]. Eigenvalues= [%f, %f], Can NOT use method\n', x0, f, gf, hf, ev);