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: DEM_demo_Cornsweet.m
    path of file: ./repos/spm/toolbox/DEM
    
    the code of the file until where you have to start completion: function DEM_demo_Cornsweet
% The Cornsweet effect: This demo illustrates the inference underlying the
% Cornsweet effect or illusion. It exploits formal priors on the spatial
% contiguity of the illuminant and reflectance; where the illuminant does not
% have edges, but the reflectance can. This is implemented using a
% discrete cosine set (DCT) as the spatial basis for the illuminant and a 
% (Haar) Discrete Wavelet transform (DWT) for the reflectance. Appropriate
% shrinkage priors on the (implicit) transform coefficients ensure that the
% explanation for visual input (reflectance times illuminant) assigns edges
% to the reflectance; thereby producing the Cornsweet effect.
%______________________________
    
function of precision (contrast)
%--------------------------------------------------------------------------
spm_figure('GetWin','Figure 3'); clf
 
subplot(3,1,1)
spm_plot_ci(d1,v1,C),                hold on
plot(C,d1,'ob',C,C*0,'LineWidth',2), hold off
title('Conditional difference (Cornsweet)','FontSize',16)
xlabel('log-precision (contrast)','FontSize',12)
ylabel('reflectance difference','FontSize',12)
spm_axis tight square
 
subplot(3,1,2)
spm_plot_ci(d2,v2,C),                hold on
plot(C,d2,'or',C,C*0,'LineWidth',2), hold off
title('Conditional difference (Mach Band)','FontSize',16)
xlabel('log-precision (contrast)','FontSize',12)
ylabel('reflectance difference','FontSize',12)
spm_axis tight square
 
% and associated percepts
%--------------------------------------------------------------------------
colormap([1:255]'*[1 1 1]/255)
j     = [1 5 7];
nj    = length(j);
for i = 1:nj
   
    % predictions
    %----------------------------------------------------------------------
    PR    = P.R*SIM{j(i)}.qU.x{1};
    PR    = PR*256 + 128;
    
    subplot(3,nj,i + 2*nj)
    image(PR)
    ylabel('eccentricity','FontSize',12)
    axis square
 
end