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: spm_mci_fixed.m
    path of file: ./repos/spm/toolbox/mci/inference
    
    the code of the file until where you have to start completion: function [Psamp,noise,M] = spm_mci_fixed (mcmc,w,fixed,noise,M,U,Y)
% Group fixed effects estimation
% FORMAT [Psamp,noise,M] = spm_mci_fixed (mcmc,w,fixed,noise,M,U,Y)
%
% mcmc      Sampling parameters
% w(:,n)    Random effects for nth subject
% fixed     [fixed.pE, fixed.pC] prior over fixed effects
% noise     noise structure
% M,U,Y     Model, input, data structures
%
% Psamp     Samples, [maxits x M{1}.Np] 
% noise     updated noise model
% M         updated model structures
%
% Uses Langevin Monte Carlo

    
function [Psamp,noise,M] = spm_mci_fixed (mcmc,w,fixed,noise,M,U,Y)
% Group fixed effects estimation
% FORMAT [Psamp,noise,M] = spm_mci_fixed (mcmc,w,fixed,noise,M,U,Y)
%
% mcmc      Sampling parameters
% w(:,n)    Random effects for nth subject
% fixed     [fixed.pE, fixed.pC] prior over fixed effects
% noise     noise structure
% M,U,Y     Model, input, data structures
%
% Psamp     Samples, [maxits x M{1}.Np] 
% noise     updated noise model
% M         updated model structures
%
% Uses Langevin Monte Carlo
%__________________________________________________________________________

% Will Penny
% Copyright (C) 2015 Wellcome Trust Centre for Neuroimaging

try, verbose=mcmc.verbose; catch, verbose=0; end