i have made a matlab code of gauss-siedel but there's a slight problem . i need to make the output print 20 iteration but i only get 18. any advice?

%6x-y-z=19
%3x+4y+z=26
%x+2y+6z=22
%initial values for y and z is 0
%x=19+y+z/6
%y=26-3x-z/4
%z=22-x-2y/6
clear;clc;format('long','g');
i=1;
y(i)=0;
z(i)=0;
error_x(i)=1;
%gauss-siedel opperation begin
while error_x(i) >= 0.00000000000000001
    x(i+1)=((19 + y(i) +z(i) )/6);
    y(i+1)=((26 - (3*x(i+1))- z(i)) /4);
    z(i+1)=((22 - x(i+1)- 2*y(i+1)) /6);
    
    error_x(i+1)=abs((x(i+1)-x(i))/x(i+1))*100;
    error_y(i+1)=abs((y(i+1)-y(i))/y(i+1))*100;
    error_z(i+1)=abs((z(i+1)-z(i))/z(i+1))*100;
    
    i=i+1;
end
%print out the value
disp('          x                       error(%)');
disp([x',       error_x'])
disp('          y                       error(%)');
disp([y',       error_y'])
disp('          z                       error(%)');
disp([z',       error_z'])

Answer 1

[Cris LaPierre]

If you need a specific number of iteractions, use a for loop instead of a while loop.

[ricky fajar]

thank you for your advice