lu_gauss.m

sareli<matlab科学计算>配套程序

function A=lu_gauss(A)
%LU_GAUSS     LU factorization without pivoting.
%   A = LU(A) stores an upper triangular matrix in the upper
%   triangular part of A and a lower triangular matrix in the
%   strictly lower part of A (the diagonal elements of L are 1). 
[n,m]=size(A);
if n ~= m; error('A is not a square matrix'); else
 for k = 1:n-1 
   for i = k+1:n
     A(i,k) = A(i,k)/A(k,k);
     if A(k,k) == 0, error('Null diagonal element'); end
     for j = k+1:n  
       A(i,j) = A(i,j) - A(i,k)*A(k,j);
     end
   end
 end
end

return