clear all; close all; clc;

% x=sym('x',[2,1]);
% f=(x(1)+2*x(2)-7)^2+(2*x(1)+x(2)-5)^2;
% df=gradient(f);
% H=hessian(f);
% f=matlabFunction(f,'Vars',([x(1);x(2)]));
% df=matlabFunction(df,'Vars',([x(1);x(2)]));
% H=matlabFunction(H,'Vars',([x(1);x(2)]));

f=@(x)(x(1)+2*x(2)-7)^2+(2*x(1)+x(2)-5)^2;
df=@(x)[10*x(1)+8*x(2)-34;
    8*x(1)+10*x(2)-38];
H=[10,8;8,10];

xmin=[-10;10];
xmax=[10;10];

x1=linspace(xmin(1),xmax(1),50);
x2=linspace(xmin(2),xmax(2),50);
y=zeros(50);

for i=1:50
    for j=1:50
        y(j,i)=f([x1(i);x2(j)]);
    end
end
surf(x1,x2,y);

x0=20*rand(2,1)-10;
h=0.05;
epsilon=1e-3;
Nmax=1e3;
delta=1e-6;
x_opt=[];

i=1;
while true
    [h,x0]=naj_spadek(df,x0,x_opt);