Gauss - Seidel MATLAB

gauss.m

function x=gauss(A,b)
%This function solves system of algebraic equations using Gaussian method
%Ax=b
%Input: matrix A, column vector b
%Output vector x 
n=size(A,1);
b=b(:); %make sure b is a column vector.
nb=n+1;
Ab=[A b]; %extended matrix

%Forward process
for i=1:n-1
    for j=i+1:n
        Ab(j,i:nb)=Ab(j,i:nb)-Ab(j,i)*Ab(i,i:nb)/Ab(i,i);
    end
end
%Inverse process
x=zeros(n,1);
x(n)=Ab(n,nb)/Ab(n,n);
for i=n-1:-1:1
    x(i)=(Ab(i,nb)-Ab(i,i+1:n)*x(i+1:n))/Ab(i,i);
end
end