www.pudn.com > gpml.rar > solve_chol.m, change:2006-03-13,size:991b

% solve_chol - solve linear equations from the Cholesky factorization. % Solve A*X = B for X, where A is square, symmetric, positive definite. The % input to the function is R the Cholesky decomposition of A and the matrix B. % Example: X = solve_chol(chol(A),B); % % NOTE: The program code is written in the C language for efficiency and is % contained in the file solve_chol.c, and should be compiled using matlabs mex % facility. However, this file also contains a (less efficient) matlab % implementation, supplied only as a help to people unfamiliar with mex. If % the C code has been properly compiled and is avaiable, it automatically % takes precendence over the matlab code in this file. % % Copyright (c) 2004, 2005, 2006 by Carl Edward Rasmussen. 2006-02-08. function x = solve_chol(A, B); if nargin ~= 2 | nargout > 1 error('Wrong number of arguments.'); end if size(A,1) ~= size(A,2) | size(A,1) ~= size(B,1) error('Wrong sizes of matrix arguments.'); end x = A\(A'\B);