%% Computer Lab:  Best Basis
%  Name:


% Always a good idea to clear any old variables out:
clear
clc

%% 1.  Load the data:
load author.mat
Y1=double(Y1);

%% 2.  Visualize the data 
%  (you can comment this out once you've seen it)

for j=1:109
	imagesc( reshape(Y1(:,j),120,160) );
	if j==1
		colormap(gray);
	end
	M(j)=getframe;
end

movie(M)

%% 3.  Compute the mean and visualize as an image:


%% 4-5 Visualize the mean-subtracted data as an image
%  You can skip the visualization step, but not the mean subtraction!


%% 5. Find the best basis.


%% 6. Visualize the first four basis vectors 
%  Here, I'm assuming they are the columns of a matrix U.

figure;  %If you want a new figure
for j=1:4
   subplot(2,2,j)
   imagesc(reshape(U(:,j),120,160));
end

%% 7.  Project the data to the first two dimensions, and plot the result.