function [A]=chap_2_sect_6_prob_26(A)
% slu Square lu factorization with now row exchanges, and overwritting A 
%
% Written by:
% -- 
% John L. Weatherwax                2006-03-28
% 
% email: wax@alum.mit.edu
% 
% Please send comments and especially bug reports to the
% above email address.
% 
%-----

[n,n]=size(A);
tol=1.e-6; 
for k=1:n,
  if( abs(A(k,k))< tol )
    disp(['Small pivot in column', int2str(k)]); 
  end % cannot proceed without a row exchange
  for i=k+1:n
    A(i,k) = A(i,k)/A(k,k); % the kth pivot is now A(k,k)
    for j=k+1:n
      A(i,j) = A(i,j) - A(i,k)*A(k,j); 
    end
  end
end