Miscellany

function gauss2
A=[5 -6 4; 3 -3 2; 4 -5 2]
b=[3; 2; 1]
N = max(size(A));



 for j=2:N,
     for i=j:N,
        m = A(i,j-1)/A(j-1,j-1);
        A(i,:) = A(i,:) - A(j-1,:)*m;
        b(i) = b(i) - m*b(j-1);
     end
 end


 x = zeros(N,1);
 x(N) = b(N)/A(N,N);

 for j=N-1:-1:1,
   x(j) = (b(j)-A(j,j+1:N)*x(j+1:N))/A(j,j);
 end
x