the Jacobi Iterative method(urgent)

hello , I have to Write a Matlab code to solve an n x n linear

system using the Jacobi Iterative method

I need this code to solve this problem

I wrote this code but it does not solve it correctly

A = [ 1 -1 2 -1 ;2 -2 3 -3;1 1 1 0;1 -1 4 3];
b = [-8; -20; -2; 4];
% error tolerance
tol =10^-3;

%initial guess:
x0 = zeros(4,1);
xnew=x0;
error=1;
while error>tol  
    xold=xnew;
    
    for i=1:length(xnew)
        off_diag = [1:i-1 i+1:length(xnew)];
        xnew(i) = 1/A(i,i)*( b(i)-sum(A(i,off_diag)*xold(off_diag)) );
    end
    error=norm(xnew-xold)/norm(xnew);
end
x_jacobian=xnew

the answer must be like this

can anybody help me ( the deadline for this homework tomorrow)

[Torsten]

Take A and b from the exercise. The Jacobi method is not guaranteed to converge for arbitrary matrices.

Further, use norm(...,Inf) instead of norm.

[Mahdi Almahuzi]

can anyone fix the code and send it please

[Torsten]

Wnat error do you get ?

[Mahdi Almahuzi]

All the answers are not same (wrong). and i need to get same as the second pic

[Torsten]

Did you change A and b to the data of your exercise ?

[Rik]

Your question is not urgent, the reason for that is explained here.

You can find guidelines for posting homework on this forum here.