Ex8 - Part 2

Author: mdlima

mlclass-ex8/mlclass-ex8/cofiCostFunc.m

@@ -11,7 +11,7 @@
 Theta = reshape(params(num_movies*num_features+1:end), ...
                 num_users, num_features);
 
-            
+
 % You need to return the following values correctly
 J = 0;
 X_grad = zeros(size(X));
@@ -41,16 +41,18 @@
 %
 
 
+J = sum(sum( (( (X * Theta') - Y) .* R) .^ 2 ))/2;
 
+X_grad = (( (X * Theta') - Y) .* R) * Theta;
+Theta_grad = (( (X * Theta') - Y) .* R)' * X;
 
 
+% Regularization
+J = J + lambda * (Theta(:)' * Theta(:)) / 2;
+J = J + lambda * (X(:)' * X(:)) / 2;
 
-
-
-
-
-
-
+X_grad = X_grad + lambda * X;
+Theta_grad = Theta_grad + lambda * Theta;
 
 
 

mlclass-ex8/mlclass-ex8/ex8_cofi.m

@@ -126,24 +126,37 @@
 %  Initialize my ratings
 my_ratings = zeros(1682, 1);
 
-% Check the file movie_idx.txt for id of each movie in our dataset
-% For example, Toy Story (1995) has ID 1, so to rate it "4", you can set
-my_ratings(1) = 4;
-
-% Or suppose did not enjoy Silence of the Lambs (1991), you can set
-my_ratings(98) = 2;
-
-% We have selected a few movies we liked / did not like and the ratings we
-% gave are as follows:
-my_ratings(7) = 3;
+% % Check the file movie_idx.txt for id of each movie in our dataset
+% % For example, Toy Story (1995) has ID 1, so to rate it "4", you can set
+% my_ratings(1) = 4;
+% 
+% % Or suppose did not enjoy Silence of the Lambs (1991), you can set
+% my_ratings(98) = 2;
+% 
+% % We have selected a few movies we liked / did not like and the ratings we
+% % gave are as follows:
+% my_ratings(7) = 3;
+% my_ratings(12)= 5;
+% my_ratings(54) = 4;
+% my_ratings(64)= 5;
+% my_ratings(66)= 3;
+% my_ratings(69) = 5;
+% my_ratings(183) = 4;
+% my_ratings(226) = 5;
+% my_ratings(355)= 5;
+
+
+my_ratings(1) = 5;
+my_ratings(7) = 5;
 my_ratings(12)= 5;
 my_ratings(54) = 4;
 my_ratings(64)= 5;
 my_ratings(66)= 3;
 my_ratings(69) = 5;
-my_ratings(183) = 4;
-my_ratings(226) = 5;
-my_ratings(355)= 5;
+my_ratings(98) = 4;
+my_ratings(183) = 3;
+my_ratings(226) = 4;
+my_ratings(355)= 4;
 
 fprintf('\n\nNew user ratings:\n');
 for i = 1:length(my_ratings)