% TOEP2_LOGDET          Computes the log-determinant and obtain the
% reflection coefficient for calculation of inverse-trace.
%
% [LOGDET,DS,VN1] = TOEP2_LOGDET(ct)
%
% This function uses the modified Durbin-Levinson's algorithm to calculate 
% the log-determinant of Q, where that Q is a strictly Toeplitz matrix. It
% also returns a vector and a scalar (reflection coefficient) for later
% calculation of <toep2_trace>.
%
% Input:
%       ct  = Top row of Toeplitz matrix, Q, of dimension {1 x N}
%
% Outputs:
%       LOGDET  = Log-determinant of Toeplitz matrix Q
%       DS      = Vector form for <toep2_trace> calculation
%       VN1     = Reflection coefficient for <toep2_trace> calculation
%
%
% The computation is written in C code for execution of fast algorithm.
% The origin of the fast algorithm is contributed by Y. Zhang
% (2005) for the use in Gaussian Process Prior Models.
%
%
% (C) Gaussian Process Toeplitz Toolbox 1.0
% (C) Copyright 2005-2007, Keith Neo <keith.neo@nuim.ie>
%                          http://www.hamilton.ie