function L = chol_left (A)
%CHOL_LEFT left-looking Cholesky factorization.
% Example
%   L = chol_left (A)
% See also: cs_demo

%   Copyright 2006-2007, Timothy A. Davis.
%   http://www.cise.ufl.edu/research/sparse

n = size (A,1) ;
L = zeros (n) ;
for k = 1:n
    L (k,k) = sqrt (A (k,k) - L (k,1:k-1) * L (k,1:k-1)') ;
    L (k+1:n,k) = (A (k+1:n,k) - L (k+1:n,1:k-1) * L (k,1:k-1)') / L (k,k) ;
end