You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: sfactorization_wilson.m
    path of file: ./repos/malini/Codes/deconvolution - model/spm8/external/fieldtrip/connectivity/private
    
    the code of the file until where you have to start completion: function [H, Z, S, psi] = sfactorization_wilson(S,freq,Niterations,tol,fb,init)

% Usage  : [H, Z, S, psi] = sfactorization_wilson(S,fs,freq);
% Inputs : S (1-sided, 3D-spectral matrix in the form of Channel x Channel x frequency) 
%        : fs (sampling frequency in Hz)
%        :
    
function (see Example pp. 424)
A0    = gamtmp(:,:,1); 
A0inv = inv(A0);

%Z     = A0*A0.'*fs; %Noise covariance matrix
Z     = A0*A0.'; %Noise covariance matrix not multiplied by sampling frequency

%FIXME check this; at least not multiplying it removes the need to correct later on
%this also makes it more equivalent to the noisecov estimated by biosig's mvar-function

H = zeros(m,m,N+1) + 1i*zeros(m,m,N+1);
for k = 1:N+1
  H(:,:,k) = psi(:,:,k)*A0inv;       %Transfer function
  S(:,:,k) = psi(:,:,k)*psi(:,:,k)'; %Updated cross-spectral density
end