Im getting NaN as output Help pls

Im trying to get the answer but I get NaN

function  x= numjacobi(A,b,x0,tol,trace)
[nrow, ncol]=size(A);
%
if nrow~=ncol 
    errordlg('cant calculate');
end
%
if nargin<3
    x0=ones(size(A,1),1);
end
%
if nargin<4
    x0=ones(size(A,1),1);
end
%
if nargin<5 || isempty (tol) 
    
    tol= 1e-6;          
end


b= (b(:).')';       
x0=(x0(:).')';      

n=length(b);
if n~=nrow 
    errordlg('b has different lenght than A');
end
%
if det(A)==0
    fprintf('Error')
end
%
if nargin<5 
   trace=0;
end
%% Matrix with modified coefficients and vector with modified coefficients 
D = diag(diag(A));          
a0 = (inv(D)*A)-eye(nrow);  
b0 = inv(D)*b;              

x=x0;                       
x0 = x + 2*tol;            
                            
iter=0;
%%

while max(abs(x-x0))>=tol || iter<100
    
    x0=x;                 
    x=b0-(a0)*x0;        
    iter=iter+1;
    if trace
        fprintf('\n Iteraction no %3d\n', iter)
        fprintf('%8.6g ',x)
    end
end

 
end

%%%%%
% AND IM USING THIS VECTORS AND CALL THE FUNCTION 

A=[80,2,1;60,-1,1;50,0,-1];
b=[536;678;907];
x0=[1 1 1]';
answ=numjacobi(A,b,x0,1e-6,0);
disp(answ)

Answer 1

[Cris LaPierre]

The value of x in your while loop keeps getting bigger and bigger.

At iter==1610, x = [2.6071; -Inf; -Inf] * 1.0e+306

At iter==1611, x = [Inf; NaN; NaN]

At iter==1612, x = [NaN; NaN; NaN]

There appears to be something incorrect about your calculation of x.

[Blue Matlover]

Thnks for the answer ! I just checked it and the mistake was that my code only acepts predominant diagonal matrix.... so I need to change the values of A