octave lab3

A=[3,1,-1;-1,5,-1;2,4,8]
b=[6;10;2]
wynik=A\b

[x,Ur] = f_gauss(A,b)

function [x,Ur]=f_gauss(A,b)
  [n,m]=size(A);
  x=zeros(n,1);
  if (n~=m) error('Macierz A musi byc kwadratowa'); end
	  Ur = [A,b];
   for k=1:(n-1)
     if A(k,k)==0
      error;
      end
      for jj=k+1:(n+1)
       for ii=k+1:n
       Ur(ii,jj)=Ur(ii,jj)-Ur(ii,k)*Ur(k,jj)/Ur(k,k);
       end
     end
   end

  for ii=n:-1:1
   S=0;
    for jj=ii+1:n
    S=S+Ur(ii,jj)*x(jj);
    end
  x(ii)=(Ur(ii,n+1)-S)/Ur(ii,ii);
  end
end