function [L,U] = lumatlevel(A)
% function [L,U] = lumatlevel(A)
%
% matrix level modification for lu; only one loop

[n,n] = size(A);
for k=1:n-1
        A(k+1:n,k) = A(k+1:n,k)/A(k,k);  
        A(k+1:n,k+1:n) = A(k+1:n,k+1:n) - A(k+1:n,k)*A(k,k+1:n);
end
U = triu(A);
L = eye(n)+tril(A,-1);