%*****************************************************************
%
% Decomposition of Cholesky (tridiagonal matrixes)
%
% Use:	 [v1,v2]=chol3(d1,d2)
%
% Input: d1 
%	     d2 
%
% Output: v1,v2 
%

%*****************************************************************
%
function [v1,v2]=chol3(d1,d2)
n=max(size(d1));
indk=[0:n];  % per evitare operazione calcolo indice di v1 in for
v1=zeros(d1);v2=zeros(d2);
v1(1)=sqrt(d1(1));
for k=2:n;
  v2(k)=d2(k)/v1(indk(k));
  v1(k)=sqrt(d1(k)-v2(k)^2);
end