function [l,u,p]=lu1(x)
[a,b]=size(x);
for i=1:a;
  for j=1:b;
        if i<j;
            l(i,j)=-x(i,j);
            u(i,j)=0;
            p(i,j)=0;
        elseif i>j;
            u(i,j)=-x(i,j);
            l(i,j)=0;
            p(i,j)=0;
        else
            l(i,j)=0;
            u(i,j)=0;
            p(i,j)=x(i,j);
        end
    end
end